Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/16/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1025 AM EST THU NOV 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC STATES TODAY
THEN PUSH SOUTH OF NEW ENGLAND INTO THE WEEKEND. THIS WILL ALLOW
MILDER TEMPERATURES TO MOVE INTO THE REGION. SOME MUCH NEEDED
RAIN IS EXPECTED LATE MONDAY INTO TUESDAY. A RETURN TO MUCH
COLDER WEATHER IS EXPECTED BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...TEMPERATURES HAVE CLIMBED INTO THE LOW TO MID 40S
ALREADY ACROSS MUCH OF THE AREA WITH A FEW UPPER 30S IN THE HIGHER
ELEVATIONS UNDER SUNNY SKIES. OVERALL...THE FORECAST IS ON TRACK
AND FEW EDITS WERE MADE.
7 AM UPDATE...
EVALUATING H925 TEMPERATURES EXPECTED TO BE AROUND +4-6C...AND
ASSUMING THE BOUNDARY LAYER WILL MIX-UP TO THIS PRESSURE LEVEL
RESULTING IN A DRY-ADIABATIC PROFILE THROUGHOUT...THEN IT IS
CERTAINLY PLAUSIBLE WITH THE ABUNDANT SUNSHINE /PRESENT CLOUDS
SHOULD GRADUALLY CLEAR OUT OVER THE NEXT COUPLE OF HOURS/ THAT
HIGH TEMPERATURES FOR INTERIOR NEW ENGLAND WILL GET INTO THE LOW-
50S. UTILIZING NEAR-TERM GUIDANCE SUCH AS THE HRRR FORECASTED
HIGHS AROUND THE MID-50S FOR THIS AFTERNOON. CERTAINLY
PLAUSIBLE... BUT FOR NOW TONED IT DOWN BASED ON THE PRIOR
FORECAST.
OTHERWISE THE REST OF THE FORECAST REMAINS ON TRACK OUTLINING THE
ANTICIPATED WINDS AND HIGH PRESSURE. H850 JET ON ORDER OF 35-40
KNOTS WILL MOVE OFF THE SOUTHERN NEW ENGLAND THIS MORNING...
PUSHING OFFSHORE DURING THE AFTERNOON. WILL SEE WIND GUSTS
INCREASE TO 25-30 MPH WITH SOME GUSTS TO AROUND 35 MPH ALONG THE
SOUTH COAST...CAPE COD AND THE ISLANDS.
FORECASTED HIGHS ARE FOR THE LOW-50S ACROSS THE LOWER INTERIOR...
WITH UPPER-40S ALONG THE COAST AND HIGHER TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...
W-SW WINDS CONTINUE...BUT WILL DIMINISH BY AROUND MIDNIGHT. WARM
AIR ADVECTION WILL ALSO CONTINUE TO WORK IN...WITH H85 TEMPS
AROUND +7C TO +8C THROUGH THE NIGHT. EXPECT MOSTLY CLEAR SKIES
THROUGH MIDNIGHT...THEN SOME CLOUDS WILL WORK IN. OVERNIGHT LOWS
MAY DROP AS LOW AS THE LOWER 20S INLAND WITH THE LIGHT/VRBL OR
CALM WINDS...RANGING TO AROUND 40 ON THE OUTER CAPE AND NANTUCKET.
DEWPTS WILL START TO INCREASE DURING THE NIGHT AS WELL.
FRIDAY...
AS THE HIGH MOVES OFFSHORE...W-SW WINDS WILL PICK UP AGAIN WITH
SOME GUSTS UP TO 25 MPH ACROSS SE MA AND THE S COAST. EXPECT BAND
OF HIGH CLOUDS TO MOVE OFFSHORE DURING THE DAY. IT WILL BE MILDER
WITH HIGHS IN THE 50S...RUNNING AROUND 5 DEGREES ABOVE SEASONAL
NORMALS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HEADLINES...
* DRY WEATHER FOR THE EARLY PART OF THE WEEKEND
* WIDESPREAD RAIN LATE SUNDAY POSSIBLY AS LATE AS TUESDAY
* ANOTHER SHOT OF ARCTIC AIR BY MIDWEEK INTO THE FOLLOWING WEEKEND
*/OVERVIEW AND MODEL CONSENSUS...
WHILE TRENDS ARE WELL-ESTABLISHED...SPECIFICS REMAIN UNCERTAIN. FEEL
THIS IS A CONSEQUENCE OF TWO FACTORS: ONE, THAT PACIFIC ENERGY TO
EVOLVE INTO A TROUGH ACROSS THE CONUS HAS NOT BEEN WELL SAMPLED, AND
TWO, THAT SOLUTIONS ARE HAVING DIFFICULTY AS TO THE INTERACTION AND
POSSIBLE PHASING OF DISTURBANCES OVER THE NORTH-CENTRAL ATLANTIC.
THE VARIANCE AND VARIABILITY IS CLEARLY EVIDENT PER ENSEMBLE MEMBER
SOLUTIONS WITHIN THE CLIMATE PREDICTION CENTER ANALYSIS OF FORECAST
NAO/AO TELECONNECTIONS...THOUGH A TREND TOWARDS A NEAR-NEUTRAL STATE
HAS REMAINED CONSISTENT OVER THE PAST WEEK.
GIVEN THAT BROAD-SCALE TRENDS ARE WELL-ESTABLISHED...AND FOLLOWING
GUIDANCE PROVIDED BY WPC/HPC...A BLEND OF DETERMINISTIC SOLUTIONS IS
FAVORED.
*/DAY-TO-DAY DETAILS...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...
DRY AIR AND DEEP-LAYER SUBSIDENCE WILL KEEP THE FORECAST PERIOD
QUIET. A WEAK DISTURBANCE ALOFT SATURDAY MORNING MAY RESULT IN
CLOUDS SOUTH OF THE AREA IN A REGION OF BETTER MOISTURE AVAILABILITY
AND BROAD-ASCENT. OTHERWISE...INCREASING CLOUDS INTO SATURDAY NIGHT
WITH ISENTROPIC MOIST ASCENT ALONG THE WESTERN PERIPHERY OF THE
DEPARTING RIDGE. ONSHORE FLOW WILL RESULT IN TEMPERATURES CLOSER TO
SEASONAL NORMALS...HIGHS AROUND THE LOW-50S WITH LOWS AROUND THE
MID 30S.
*/SUNDAY INTO TUESDAY...
A PERIOD OF WIDESPREAD RAIN IS CERTAIN ALONG AND AHEAD OF A COLD
FRONT. EXACT TIMING AND LONGEVITY REMAIN UNCERTAIN. NOTED EARLIER...
PWATS OF 1.5 INCHES ARE ROUGHLY 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL FOR THIS TIME OF YEAR...AND WITH STRONG FRONTOGENETICAL
FORCING AND DEEP-LAYER ASCENT...THERE IS THE THREAT OF HEAVY RAIN.
STILL SOME QUESTION AS TO WHETHER THIS WILL BE LOCALIZED SHOULD AN
AREA OF LOW PRESSURE DEVELOP ALONG THE FRONT AND ACROSS OUR AREA AS
CONTINUALLY SUGGESTED BY THE ECMWF. WITH MINOR TO MODERATE DROUGHT
ESTIMATED ACROSS THE REGION...AND THE PROGRESSIVE NATURE OF THE
FRONT AS AGREED UPON BY ALL SOLUTIONS...THERE IS LOW CONFIDENCE ON
FLOODING. ALSO THERE DOES NOT SEEM TO BE MUCH INSTABILITY...SO LOW
CONFIDENCE ON THUNDER.
STRENGTH OF THE SYSTEM...WHICH IS UNDER QUESTION...WILL ULTIMATELY
DETERMINE THE MAGNITUDE OF WARM-MOIST ADVECTION NORTHWARD PER
SOUTHERLY FLOW. STRONGEST OF WINDS WILL BE ALONG THE SOUTH-SHORELINE
BUT DO NOT FEEL THEY WILL REACH WIND ADVISORY CRITERIA. GALES WILL
BE POSSIBLE OVER THE WATERS. TIMING AND STRENGTH OF THE WINDS WILL
ALSO ULTIMATELY DETERMINE SURFACE TEMPERATURE AND DEWPOINT OUTCOMES.
*/WEDNESDAY INTO THE FOLLOWING WEEKEND...
COLD DOME OF CANADIAN HIGH PRESSURE RETURNS. BELOW-NORMAL CONDITIONS
PREVAILING INTO ROUGHLY THE END OF THE WEEK WITH THE HIGH SITUATED
NORTH AND WEST OF THE REGION...RETURNING TO SEASONABLE LEVELS BY THE
FOLLOWING WEEKEND WITH THE HIGH SHIFTING EAST RESULTING IN RETURN
SOUTHERLY FLOW.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.
VFR. INCREASING WEST-SOUTHWESTERLY FLOW WITH GUSTS AROUND 20 TO
25 KTS LATE MORNING INTO AFTERNOON...STRONGER ALONG THE SOUTH
COASTLINE WITH GUSTS OF AROUND 30 KTS POSSIBLE. WINDS RELAX
TONIGHT AS VFR CONTINUES TO PREVAIL...BUT RETURN TOMORROW ALONG
THE SOUTH AND SOUTHEAST TERMINALS WITH GUSTS OF AROUND 20 KTS LATE
MORNING INTO AFTERNOON.
KBOS TAF...HIGH CONFIDENCE IN VFR.
KBDL TAF...HIGH CONFIDENCE IN VFR.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. INCREASING
MID TO HIGH LEVEL CLOUDS.
*/SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE.
LOW-END VFR TO MVFR CIGS. WIDESPREAD -RA WITH POSSIBLE +RA RESULTING
IN IFR VSBYS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF
THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH-SHORELINE
WITH GUSTS OF AROUND 30 KTS. COLD FRONT SWEEPS THROUGH THE TERMINALS
LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...
TODAY...MODERATE TO HIGH CONFIDENCE.
W-SW WINDS WILL INCREASE AS LOW LEVEL JET MOVES ACROSS THE
SOUTHERN WATERS THROUGH MIDDAY. SMALL CRAFTS ARE UP FOR ALL
WATERS EXCEPT THE SOUTHERN OUTER WATERS TO E OF CAPE COD WHERE
GUSTS WILL REACH 35 KT. HAVE PUT GALES UP THERE. AS THE JET MOVES
OFFSHORE THIS AFTERNOON...WINDS WILL BEGIN TO SLOWLY DIMINISH.
SEAS BUILD UP TO 6-8 FT ON THE SOUTHERN WATERS.
TONIGHT...MODERATE TO HIGH CONFIDENCE.
EXPECT W-SW WINDS TO DIMINISH TONIGHT. WILL SEE GUSTS UP TO 25 KT
ON THE OUTER WATERS EARLY. SMALL CRAFTS ON THE NEAR SHORE WATERS
SHOULD COME DOWN EARLY...BUT WILL REMAIN UP ON THE OUTER WATERS
THROUGH THE NIGHT MAINLY FOR SEAS UP TO 6 FT.
FRIDAY...HIGH CONFIDENCE.
EXPECT W WINDS TO CONTINUE TO GUST UP TO 20 KT AND SEAS AOA 5 FT
ON THE SOUTHERN OUTER WATERS...THOUGH SHOULD DIMINISH DURING THE
DAY. OTHERWISE...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE.
LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. SEAS SHOULD
REMAIN BELOW 5 FEET OVER ALL WATERS.
*/SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE.
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS. EAST-SOUTHEASTERLY
WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH
WILL BE ALONG THE SOUTH WATERS WITH GUSTS OF AROUND 30 KTS POSSIBLY
EXCEEDING GALE FORCE. ANTICIPATE SEAS TO BE ABOVE 5 FEET FOR A TIME
OVER ALL WATERS EXCEPT INNER BAYS AND HARBORS.
COLD FRONT SWEEPS THROUGH THE WATERS LATE BEHIND WHICH WINDS BACK
WEST-NORTHWESTERLY REMAINING BLUSTERY. GALES MAY CONTINUE FOR ALL
WATERS. SEAS TO REMAIN CHOPPY.
&&
.FIRE WEATHER...
HIGH PRESSURE ACROSS THE MID ATLANTIC WILL MOVE OFF THE COAST WITH
RETURN W-SW FLOW IN PLACE INTO THIS WEEKEND. VERY LOW DEWPTS
REMAIN IN PLACE...IN THE TEENS EARLY THIS MORNING...WILL RISE ONLY
SLIGHTLY AWAY FROM THE S COAST...CAPE COD AND THE ISLANDS DURING
THE DAY. WILL ALSO SEE W-SW WINDS PICK UP TO 20-25 MPH WITH SOME
GUSTS TO 30 MPH ACROSS INLAND AREAS.
TODAY...MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON WILL DROP TO
BETWEEN 30 AND 35 PERCENT ACROSS AREAS AWAY FROM THE IMMEDIATE
COAST. WITH THE LACK OF RAINFALL OVER THE LAST FEW WEEKS ALONG
WITH THE INCREASING WIND ESPECIALLY ACROSS E AND CENTRAL MA/N CT
INTO N RI AND THE LOW RELATIVE HUMIDITY VALUES...THERE MAY BE
CAUSE FOR SOME CONCERN FOR FIRE WEATHER INTERESTS.
FRIDAY...MINIMUM RELATIVE HUMIDITIES WILL DROP TO BETWEEN 25 AND
35 PERCENT AGAIN AROUND MIDDAY OR EARLY AFTERNOON ACROSS AREAS
AWAY FROM THE S COAST. HOWEVER...W-SW WINDS WILL BE LOWER...
THOUGH MAY GUST UP TO 20 MPH ACROSS N RI AND INTERIOR SE MA.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ232-
251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ233-234-250.
SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ235-237.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ254>256.
&&
$$
SYNOPSIS...SIPPRELL/EVT
NEAR TERM...RLG/SIPPRELL/EVT
SHORT TERM...EVT
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/EVT
MARINE...SIPPRELL/EVT
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
642 AM EST THU NOV 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC STATES TODAY
THEN PUSH SOUTH OF NEW ENGLAND INTO THE WEEKEND. THIS WILL ALLOW
MILDER TEMPERATURES TO MOVE INTO THE REGION. SOME MUCH NEEDED
RAIN IS EXPECTED LATE MONDAY INTO TUESDAY. A RETURN TO MUCH
COLDER WEATHER IS EXPECTED BY THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
CONDITIONS ARE ACTUALLY WARMING BY A FEW DEGREES EARLY THIS
MORNING WITH THE ONSHORE SOUTHWESTERLY FLOW. AS OF 4 AM...
TEMPERATURES ACROSS SOUTHEAST NEW ENGLAND HAD WARMED BY A FEW
DEGREES...PRIOR TO SUNRISE.
EVALUATING H925 TEMPERATURES EXPECTED TO BE AROUND +4-6C...AND
ASSUMING THE BOUNDARY LAYER WILL MIX-UP TO THIS PRESSURE LEVEL
RESULTING IN A DRY-ADIABATIC PROFILE THROUGHOUT...THEN IT IS
CERTAINLY PLAUSIBLE WITH THE ABUNDANT SUNSHINE /PRESENT CLOUDS
SHOULD GRADUALLY CLEAR OUT OVER THE NEXT COUPLE OF HOURS/ THAT
HIGH TEMPERATURES FOR INTERIOR NEW ENGLAND WILL GET INTO THE LOW-
50S. UTILIZING NEAR- TERM GUIDANCE SUCH AS THE HRRR FORECASTED
HIGHS AROUND THE MID-50S FOR THIS AFTERNOON. CERTAINLY PLAUSIBLE...
BUT FOR NOW TONED IT DOWN BASED ON THE PRIOR FORECAST.
OTHERWISE THE REST OF THE FORECAST REMAINS ON TRACK OUTLINING THE
ANTICIPATED WINDS AND HIGH PRESSURE. H850 JET ON ORDER OF 35-40
KNOTS WILL MOVE OFF THE SOUTHERN NEW ENGLAND THIS MORNING...
PUSHING OFFSHORE DURING THE AFTERNOON. WILL SEE WIND GUSTS
INCREASE TO 25-30 MPH WITH SOME GUSTS TO AROUND 35 MPH ALONG THE
SOUTH COAST...CAPE COD AND THE ISLANDS.
FORECASTED HIGHS ARE FOR THE LOW-50S ACROSS THE LOWER INTERIOR...
WITH UPPER-40S ALONG THE COAST AND HIGHER TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...
W-SW WINDS CONTINUE...BUT WILL DIMINISH BY AROUND MIDNIGHT. WARM
AIR ADVECTION WILL ALSO CONTINUE TO WORK IN...WITH H85 TEMPS
AROUND +7C TO +8C THROUGH THE NIGHT. EXPECT MOSTLY CLEAR SKIES
THROUGH MIDNIGHT...THEN SOME CLOUDS WILL WORK IN. OVERNIGHT LOWS
MAY DROP AS LOW AS THE LOWER 20S INLAND WITH THE LIGHT/VRBL OR
CALM WINDS...RANGING TO AROUND 40 ON THE OUTER CAPE AND NANTUCKET.
DEWPTS WILL START TO INCREASE DURING THE NIGHT AS WELL.
FRIDAY...
AS THE HIGH MOVES OFFSHORE...W-SW WINDS WILL PICK UP AGAIN WITH
SOME GUSTS UP TO 25 MPH ACROSS SE MA AND THE S COAST. EXPECT BAND
OF HIGH CLOUDS TO MOVE OFFSHORE DURING THE DAY. IT WILL BE MILDER
WITH HIGHS IN THE 50S...RUNNING AROUND 5 DEGREES ABOVE SEASONAL
NORMALS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HEADLINES...
* DRY WEATHER FOR THE EARLY PART OF THE WEEKEND
* WIDESPREAD RAIN LATE SUNDAY POSSIBLY AS LATE AS TUESDAY
* ANOTHER SHOT OF ARCTIC AIR BY MIDWEEK INTO THE FOLLOWING WEEKEND
*/OVERVIEW AND MODEL CONSENSUS...
WHILE TRENDS ARE WELL-ESTABLISHED...SPECIFICS REMAIN UNCERTAIN. FEEL
THIS IS A CONSEQUENCE OF TWO FACTORS: ONE, THAT PACIFIC ENERGY TO
EVOLVE INTO A TROUGH ACROSS THE CONUS HAS NOT BEEN WELL SAMPLED, AND
TWO, THAT SOLUTIONS ARE HAVING DIFFICULTY AS TO THE INTERACTION AND
POSSIBLE PHASING OF DISTURBANCES OVER THE NORTH-CENTRAL ATLANTIC.
THE VARIANCE AND VARIABILITY IS CLEARLY EVIDENT PER ENSEMBLE MEMBER
SOLUTIONS WITHIN THE CLIMATE PREDICTION CENTER ANALYSIS OF FORECAST
NAO/AO TELECONNECTIONS...THOUGH A TREND TOWARDS A NEAR-NEUTRAL STATE
HAS REMAINED CONSISTENT OVER THE PAST WEEK.
GIVEN THAT BROAD-SCALE TRENDS ARE WELL-ESTABLISHED...AND FOLLOWING
GUIDANCE PROVIDED BY WPC/HPC...A BLEND OF DETERMINISTIC SOLUTIONS IS
FAVORED.
*/DAY-TO-DAY DETAILS...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...
DRY AIR AND DEEP-LAYER SUBSIDENCE WILL KEEP THE FORECAST PERIOD
QUIET. A WEAK DISTURBANCE ALOFT SATURDAY MORNING MAY RESULT IN
CLOUDS SOUTH OF THE AREA IN A REGION OF BETTER MOISTURE AVAILABILITY
AND BROAD-ASCENT. OTHERWISE...INCREASING CLOUDS INTO SATURDAY NIGHT
WITH ISENTROPIC MOIST ASCENT ALONG THE WESTERN PERIPHERY OF THE
DEPARTING RIDGE. ONSHORE FLOW WILL RESULT IN TEMPERATURES CLOSER TO
SEASONAL NORMALS...HIGHS AROUND THE LOW-50S WITH LOWS AROUND THE
MID 30S.
*/SUNDAY INTO TUESDAY...
A PERIOD OF WIDESPREAD RAIN IS CERTAIN ALONG AND AHEAD OF A COLD
FRONT. EXACT TIMING AND LONGEVITY REMAIN UNCERTAIN. NOTED EARLIER...
PWATS OF 1.5 INCHES ARE ROUGHLY 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL FOR THIS TIME OF YEAR...AND WITH STRONG FRONTOGENETICAL
FORCING AND DEEP-LAYER ASCENT...THERE IS THE THREAT OF HEAVY RAIN.
STILL SOME QUESTION AS TO WHETHER THIS WILL BE LOCALIZED SHOULD AN
AREA OF LOW PRESSURE DEVELOP ALONG THE FRONT AND ACROSS OUR AREA AS
CONTINUALLY SUGGESTED BY THE ECMWF. WITH MINOR TO MODERATE DROUGHT
ESTIMATED ACROSS THE REGION...AND THE PROGRESSIVE NATURE OF THE
FRONT AS AGREED UPON BY ALL SOLUTIONS...THERE IS LOW CONFIDENCE ON
FLOODING. ALSO THERE DOES NOT SEEM TO BE MUCH INSTABILITY...SO LOW
CONFIDENCE ON THUNDER.
STRENGTH OF THE SYSTEM...WHICH IS UNDER QUESTION...WILL ULTIMATELY
DETERMINE THE MAGNITUDE OF WARM-MOIST ADVECTION NORTHWARD PER
SOUTHERLY FLOW. STRONGEST OF WINDS WILL BE ALONG THE SOUTH-SHORELINE
BUT DO NOT FEEL THEY WILL REACH WIND ADVISORY CRITERIA. GALES WILL
BE POSSIBLE OVER THE WATERS. TIMING AND STRENGTH OF THE WINDS WILL
ALSO ULTIMATELY DETERMINE SURFACE TEMPERATURE AND DEWPOINT OUTCOMES.
*/WEDNESDAY INTO THE FOLLOWING WEEKEND...
COLD DOME OF CANADIAN HIGH PRESSURE RETURNS. BELOW-NORMAL CONDITIONS
PREVAILING INTO ROUGHLY THE END OF THE WEEK WITH THE HIGH SITUATED
NORTH AND WEST OF THE REGION...RETURNING TO SEASONABLE LEVELS BY THE
FOLLOWING WEEKEND WITH THE HIGH SHIFTING EAST RESULTING IN RETURN
SOUTHERLY FLOW.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.
VFR. DISSIPATING MID- TO UPPER-LEVEL CIGS. INCREASING WEST-
SOUTHWESTERLY FLOW WITH GUSTS AROUND 20 TO 25 KTS LATE MORNING
INTO AFTERNOON...STRONGER ALONG THE SOUTH COASTLINE WITH GUSTS OF
AROUND 30 KTS POSSIBLE. WINDS RELAX TONIGHT AS VFR CONTINUES TO
PREVAIL...BUT RETURN TOMORROW ALONG THE SOUTH AND SOUTHEAST
TERMINALS WITH GUSTS OF AROUND 20 KTS LATE MORNING INTO AFTERNOON.
KBOS TAF...HIGH CONFIDENCE IN VFR.
KBDL TAF...HIGH CONFIDENCE IN VFR.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. INCREASING
MID TO HIGH LEVEL CLOUDS.
*/SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE.
LOW-END VFR TO MVFR CIGS. WIDESPREAD -RA WITH POSSIBLE +RA RESULTING
IN IFR VSBYS. EAST-SOUTHEASTERLY WINDS INITIALLY INCREASING OUT OF
THE SOUTH THE STRONGEST OF WHICH WILL BE ALONG THE SOUTH-SHORELINE
WITH GUSTS OF AROUND 30 KTS. COLD FRONT SWEEPS THROUGH THE TERMINALS
LATE BEHIND WHICH WINDS BACK WEST-NORTHWESTERLY REMAINING BLUSTERY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH THURSDAY NIGHT/...
TODAY...MODERATE TO HIGH CONFIDENCE.
W-SW WINDS WILL INCREASE AS LOW LEVEL JET MOVES ACROSS THE
SOUTHERN WATERS THROUGH MIDDAY. SMALL CRAFTS ARE UP FOR ALL
WATERS EXCEPT THE SOUTHERN OUTER WATERS TO E OF CAPE COD WHERE
GUSTS WILL REACH 35 KT. HAVE PUT GALES UP THERE. AS THE JET MOVES
OFFSHORE THIS AFTERNOON...WINDS WILL BEGIN TO SLOWLY DIMINISH.
SEAS BUILD UP TO 6-8 FT ON THE SOUTHERN WATERS.
TONIGHT...MODERATE TO HIGH CONFIDENCE.
EXPECT W-SW WINDS TO DIMINISH TONIGHT. WILL SEE GUSTS UP TO 25 KT
ON THE OUTER WATERS EARLY. SMALL CRAFTS ON THE NEAR SHORE WATERS
SHOULD COME DOWN EARLY...BUT WILL REMAIN UP ON THE OUTER WATERS
THROUGH THE NIGHT MAINLY FOR SEAS UP TO 6 FT.
FRIDAY...HIGH CONFIDENCE.
EXPECT W WINDS TO CONTINUE TO GUST UP TO 20 KT AND SEAS AOA 5 FT
ON THE SOUTHERN OUTER WATERS...THOUGH SHOULD DIMINISH DURING THE
DAY. OTHERWISE...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
OUTLOOK...FRIDAY NIGHT THROUGH MONDAY NIGHT...
*/FRIDAY NIGHT INTO SATURDAY NIGHT...HIGH CONFIDENCE.
LIGHT AND VARIABLE WINDS BECOMING EASTERLY LATE. SEAS SHOULD
REMAIN BELOW 5 FEET OVER ALL WATERS.
*/SUNDAY INTO MONDAY NIGHT...MODERATE CONFIDENCE.
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS. EAST-SOUTHEASTERLY
WINDS INITIALLY INCREASING OUT OF THE SOUTH THE STRONGEST OF WHICH
WILL BE ALONG THE SOUTH WATERS WITH GUSTS OF AROUND 30 KTS POSSIBLY
EXCEEDING GALE FORCE. ANTICIPATE SEAS TO BE ABOVE 5 FEET FOR A TIME
OVER ALL WATERS EXCEPT INNER BAYS AND HARBORS.
COLD FRONT SWEEPS THROUGH THE WATERS LATE BEHIND WHICH WINDS BACK
WEST-NORTHWESTERLY REMAINING BLUSTERY. GALES MAY CONTINUE FOR ALL
WATERS. SEAS TO REMAIN CHOPPY.
&&
.FIRE WEATHER...
HIGH PRESSURE ACROSS THE MID ATLANTIC WILL MOVE OFF THE COAST WITH
RETURN W-SW FLOW IN PLACE INTO THIS WEEKEND. VERY LOW DEWPTS
REMAIN IN PLACE...IN THE TEENS EARLY THIS MORNING...WILL RISE ONLY
SLIGHTLY AWAY FROM THE S COAST...CAPE COD AND THE ISLANDS DURING
THE DAY. WILL ALSO SEE W-SW WINDS PICK UP TO 20-25 MPH WITH SOME
GUSTS TO 30 MPH ACROSS INLAND AREAS.
TODAY...MINIMUM RELATIVE HUMIDITIES THIS AFTERNOON WILL DROP TO
BETWEEN 30 AND 35 PERCENT ACROSS AREAS AWAY FROM THE IMMEDIATE
COAST. WITH THE LACK OF RAINFALL OVER THE LAST FEW WEEKS ALONG
WITH THE INCREASING WIND ESPECIALLY ACROSS E AND CENTRAL MA/N CT
INTO N RI AND THE LOW RELATIVE HUMIDITY VALUES...THERE MAY BE
CAUSE FOR SOME CONCERN FOR FIRE WEATHER INTERESTS.
FRIDAY...MINIMUM RELATIVE HUMIDITIES WILL DROP TO BETWEEN 25 AND
35 PERCENT AGAIN AROUND MIDDAY OR EARLY AFTERNOON ACROSS AREAS
AWAY FROM THE S COAST. HOWEVER...W-SW WINDS WILL BE LOWER...
THOUGH MAY GUST UP TO 20 MPH ACROSS N RI AND INTERIOR SE MA.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ232.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ233-234.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM EST THIS
AFTERNOON FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ251.
GALE WARNING FROM 10 AM THIS MORNING TO 6 PM EST THIS EVENING
FOR ANZ254>256.
&&
$$
SYNOPSIS...SIPPRELL/EVT
NEAR TERM...SIPPRELL/EVT
SHORT TERM...EVT
LONG TERM...SIPPRELL
AVIATION...SIPPRELL/EVT
MARINE...SIPPRELL/EVT
FIRE WEATHER...EVT
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
942 PM EST FRI NOV 15 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO REMAIN OFFSHORE IN THE ATLANTIC
OVERNIGHT. A COLD FRONT APPROACHES FROM THE WEST AND CROSSES THE
AREA SUNDAY NIGHT INTO MONDAY MORNING. ANOTHER HIGH PRESSURE
BUILDS FROM THE NORTH ON TUESDAY. HIGH PRESSURE WILL REMAIN TO THE
NORTH INTO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A COMBINATION OF THE GFS AND CAN RGEM HAS VERIFIED THE BEST WITH
THE ONGOING PCPN. OVERALL NO BIG CHANGES AS AN UPPER AIR IMPULSE
WILL FIND A LESS HOSPITABLE ENVIRONMENT FOR PCPN TO MAKE IT TO
THE GROUND, ESPECIALLY THE NORTHERN PART OF OUR CWA. THE BIGGEST
ADJUSTMENT HAS BEEN TO TEMPERATURES AS A CIRRUS HOLE HAS DEVELOPED
OVER OUR CWA AND HAS PERMITTED TEMPERATURES TO DROP LIKE A ROCK
WITH LIGHT WINDS AND LOW DEW POINTS. WE HAVE PRACTICALLY RADIATED
TO THE DEW POINT IN SOME PLACES, SO BETWEEN THE THICKER CIRRUS
NOW AS CLOSE AS THE MD EASTERN SHORE ARRIVING AND PRETTY MUCH NO
WHERE TO GO, PLENTY OF OUTLYING AREA MINS ARE GOING TO BE
OCCURRING BEFORE MIDNIGHT BEFORE TEMPERATURE REBOUND WITH THE
ARRIVAL OF THICKER CLOUDS.
SURFACE HIGH PRESSURE TO OUR EAST WILL WEAKEN A BIT OVERNIGHT. AT
THE SAME TIME, A WEAK OPEN WAVE AT THE MID LEVELS WILL MOVE ACROSS
THE APPALACHIANS, BEFORE MOVING OFF THE NORTHERN MID-ATLANTIC COAST.
IN RESPONSE TO 12Z DATA, POPS HAVE BEEN ADJUSTED ACROSS THE DELMARVA
(INCREASED) AND ALSO HAVE BEEN ADDED A BIT FURTHER TO THE NORTH.
WINDS WILL BE LIGHT OUT OF THE SOUTHWEST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
LATEST MODEL GUIDANCE SUGGESTING A SLOWER EXIT OF PCPN CHANCES IN
SERN NJ AND DE ON SATURDAY MORNING. GIVEN THE HRRR AND WRF-NMMB
NORMALLY HAVE A SLOW TIMING BIAS, ONLY A MODEST INCREASE IN POPS WAS
DONE AT THE START OF THE MORNING.
THE MID-LEVEL SHORT WAVE WILL CONTINUE TO PRESS TO THE EAST TOMORROW
TAKING THE THREAT OF SHOWERS WITH IT. TIMING WISE...POPS START TO
SHRINK EASTWARD TOWARD DAYBREAK AND ALL POPS HAVE BEEN REMOVED BY
MIDDAY. TOTAL QPF AMOUNTS SHOULD RANGE FROM ABOUT A .10 ACROSS THE
DELMARVA TO JUST A FEW HUNDREDTHS FURTHER NORTH.
ONCE THE SHORT WAVE PULLS EAST, WE SHOULD SEE SOME DECREASE IN CLOUDS
ESPECIALLY UP ACROSS THE NORTHERN ZONES.
WINDS WILL SHIFT FROM THE SOUTHWEST AT DAYBREAK TO THE SOUTHEAST
LATER IN THE DAY.
TEMPERATURES WILL TOP OUT NEAR 50 ACROSS THE FAR NORTHWESTERN ZONES
TO AROUND 60 ON THE COASTAL PLAIN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WILL BE OFFSHORE AT THE BEGINNING OF THE EXTENDED
PERIOD. THE RETURN FLOW AROUND IT WILL BE USHERING IN MOISTURE AND
MILDER TEMPERATURES FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT. THIS
MOISTURE ALONG WITH AN APPROACHING LOW/FRONT SUNDAY NIGHT WILL BRING
HIGHER CHC FOR PCPN BEGINNING SUN NIGHT AND LASTING INTO MONDAY. A
COLD FRONT WILL CROSS THE AREA MONDAY MORNING WITH DRIER AND COLDER
AIR FLOWING IN BEHIND IT. POPS FOR THE SUN NIGHT/MONDAY PERIOD REACH
THE CATEGORICAL RANGE...THEN DROP BACK TO THE CHC RANGE FOR A FEW
HOURS FOLLOWING THE FRONT. TEMPERATURES FROM SAT NIGHT THROUGH SUN
NIGHT WILL BE ABOVE NORMAL...PERHAPS AS MUCH AS 10 DEGREES ABOVE
NORMAL SUN AND SUN NIGHT. OVERALL QPF FROM THE SYSTEM LOOKS TO BE
AROUND 0.5 TO 1.0 INCHES.
THE COLDER AIR WILL DEEPEN ACROSS THE REGION MON NIGHT AND PERSIST
THROUGH THE MID-WEEK PERIOD. STRONG HIGH PRESSURE WILL MOVE ACROSS
THE OHIO VALLEY AND GREAT LAKES MON/TUE...THEN SPRAWL ACROSS THE
MIDDLE ATLANTIC AND NORTHEAST WED/THU. THIS HIGH WILL KEEP THE
WEATHER DRY ACROSS THE AREA. TEMPERATURES WILL MODERATE BACK TO NEAR
NORMAL FOR THE LAST TWO DAYS OF THE WORK WEEK.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THE 00Z TAFS CONTINUED THE PRECIP CHANCES OVERNIGHT INTO SATURDAY
MORNING WITH SOME MVFR CONDITIONS POSSIBLE.
REST OF THIS EVENING...VFR MID OR MORE LIKELY CIRRUS DECK CIG.
WINDS LIGHT AND VARIABLE.
OVERNIGHT...VFR CIGS SHOULD LOWER TO A MID DECK AND THEN A LOWER
VFR STRATOCU DECK LEVEL WITH LIGHT AND VARIABLE WINDS.
PRECIPITATION IS LIKELY TO OVERSPREAD THE TERMINALS, BUT BE VERY
LIGHT NORTH AND WEST OF THE KPHL METRO AIRPORTS. PCPN ASSOCIATED
MVFR CIG RESTRICTIONS ARE AT KMIV AND KACY TOWARD MORNING, NOT
CONFIDENT ABOUT INCLUDING IN THE KPHL AREAS AIRPORTS AND FARTHER TO
THE NORTHWEST NOT EXPECTING IT TO OCCUR.
SATURDAY MORNING...RAIN CHANCES ENDING AT SERN AIRPORTS ALONG WITH
MVFR CIG CONCERNS. ELSEWHERE, THE VFR SC CIG SHOULD BE GONE (AND
REPLACED WITH A CIRRUS CIG) AS THE MORNING PROGRESSES. A LIGHT SE
WIND FORECAST.
SATURDAY AFTERNOON...VFR WITH LIGHT SOUTHEAST WINDS. A SCATTERED
STRATOCU/CU DECK IS FORECAST WITH THE MOST LIKELY CIG BEING AT
CIRRUS LEVELS.
AT KPHL WE INCLUDED A FORECAST GROUP SHOWING MVFR CONDITIONS
DEVELOPING LATE SATURDAY EVENING.
OUTLOOK...
SAT NIGHT THRU MONDAY...MVFR/IFR CONDITIONS WITH LOW CLOUDS AND
FREQUENT SHOWERS. GUSTY S/SW WINDS UNTIL MONDAY THEN WINDS SHIFT
TO W/NW.
MON EVENING THRU WED...MOSTLY VFR.
&&
.MARINE...
NO HEADLINES IN THE SHORT TERM....
TONIGHT...IN GENERAL, OUR WATERS WILL SEE THE SOUTHWEST WINDS
SLACKEN A BIT AND BECOME MORE WESTERLY. SEAS WILL BE 2 TO 3 FEET ON
THE OCEAN, LESS ON THE DELAWARE BAY.
SATURDAY...WINDS WILL GO VARIABLE FOR A SHORT TIME AS THEY
TRANSITION FROM THE SOUTHWEST TO THE SOUTHEAST. WINDS LOOK LIGHT IN
THE 5 TO 10 KT RANGE. SEAS WILL RUN ABOUT 2 FEET ON THE OCEAN AND
LESS ON DELAWARE BAY.
OUTLOOK...
SAT NIGHT THRU SUN AFTERNOON...INCREASING WINDS/SEAS BUT
CONDITIONS SUB-SCA.
SUN EVENING THRU TUESDAY...SCA CONDITIONS EXPECTED WITH A STORM
SYSTEM AND COLD FRONT CROSSING THE WATERS MONDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA/RODRIGUES
NEAR TERM...GIGI/KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...KRUZDLO/O`HARA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
822 PM EST Fri Nov 15 2013
.NEAR TERM [Through Rest of Tonight]...
The large scale regional pattern is highlighted this evening by a
broad H5 trough with its axis across TN Valley Swd to MS and into
the Nrn Gulf of Mexico, with weak shortwaves over E/Cntrl AL and in
the NE Gulf. At surface, an area of high pressure resides over the
Wrn Atlc east of NC with its ridge axis Swwd into the NE Gulf of
Mexico. The combination of the approaching trough/shortwaves with
WLY steering flow aloft, weak isentropic lift, and light onshore
flow brought a broad area of light rain or drizzle across CWFA
Fri afternoon and evening, keeping extensive cloud cover and
moisture in place.
By sunrise Sat, the aforementioned trough axis will have reached
Suwannee Valley with the Gulf shortwave exiting our waters. This
will continue to push any remaining light rain in southeast parts of
our region Ewd, with noticeably diminished forcing in the wake of
the trough. Both the GFS and NAM show a very weak mid/upper ridge
moving over our area between 02z-08z. HRRR and other HI RES models
show light rain or drizzle continuing to push off to the southeast
of our region by 03Z. However, with RAP13 soundings showing that
area PWATs will remain between 1.2 and 1.5 inches through the night,
and with the surface high to our NE, cool low level NE flow on top
of residual moisture from today`s rain will help support the
development of low clouds and patchy fog overnight. Chances of fog
are greatest in our GA and AL counties. Overnight low temperatures
will be mild, generally in the low to mid 50s inland, and near 60 in
coastal regions.
&&
.SHORT TERM [Saturday Through Sunday Night]...
Except for some lingering moisture/lift in our North FL zones, most
of our forecast area will be under the influence of 500 mb ridging
Saturday. We have low PoPs (generally around 20%) for Saturday and
Saturday night. The PoP will increase Sunday from northwest to
southeast as a cold front approaches. The timing of the highest
rain chances (around 70%) will be Sunday night and Monday, though
the QPF/omega fields suggest that the frontal rain band will be
weakening as it moves through. The prospects for severe storms
appear low due to poor instability, marginal vertical wind shear,
and weakening Q-G forcing. Temperatures will be above average,
though abundant clouds will help prevent high temperatures from
reaching 80 deg (except around Cross City Sunday afternoon). The
lows Sunday morning will be unusually warm- in the mid 60s.
&&
.LONG TERM [Monday through Friday]...
The relatively zonal 500 mb flow over the Gulf Coast states will
give way to ridging late in the work week. There was some
discrepancy between the GFS and ECMWF Tuesday and Wednesday, as the
GFS keeps a band of deep layer moisture and weak Q-G forcing near
the Gulf Coast as a weak short wave or two translate quickly
eastward. The ECMWF has very dry air firmly entrenched over the
Southeast and most of the Gulf of Mexico. Even if the GFS verified,
the GFS MOS PoP is still low so the main effect for our region would
be mostly cloudy skies and a slight reduction on high temperatures.
Temperatures will warm to above average Friday as the 500 mb ridge
peaks over the Southeast.
&&
.AVIATION...
UPDATED AT 820 PM
All rainfall has ended for the evening, and all sites are
currently VFR. Restrictions will be imposed later tonight as MVFR
to IFR ceilings overspread all of our terminals. Deterioration
will generally start from the east but quickly fill in everywhere
by 09z. Ceilings will scatter to VFR at all terminals but KECP by
midday. However, MVFR ceiling will return to KTLH and KVLD later
in the afternoon as more rain spreads inland from the coast.
&&
.MARINE...
UPDATED AT 820 PM
Recent buoy obs indicated that offshore winds and seas during the
mid-eve period were running at marginal advisory level conditions.
They should drop below advisory levels during the predawn hours but
remain at high end cautionary levels offshore into Saturday evening.
Winds and seas will subside Sunday and Monday as the pressure
gradient loosens near the cold front. Winds and seas will increase
Monday night behind the cold front.
&&
.FIRE WEATHER...
No immediate fire weather concerns as relative humidity values will
remain above critical levels through Monday. Drier air will begin to
arrive on Tuesday, though RH levels should stay above red flag
values.
&&
.HYDROLOGY...
Rainfall totals for the remainder of today will be negligible. The
next rain event (associated with the cold front Sunday and Monday)
will produce 0.5 to 0.75 inches across much of the forecast area. This
will be far below local Flash Flood Guidance, so the threat of
flash flooding and/or riverine flooding is minimal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 57 74 66 76 66 / 20 20 20 40 70
Panama City 60 73 68 77 69 / 20 30 20 50 70
Dothan 53 72 65 77 65 / 30 20 20 60 70
Albany 52 74 64 78 66 / 30 20 20 50 70
Valdosta 55 75 64 78 66 / 20 20 20 40 70
Cross City 59 77 65 80 67 / 70 30 20 30 50
Apalachicola 62 73 69 76 69 / 30 30 20 40 70
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...SMALL CRAFT ADVISORY until 4 AM EST Saturday for Waters from
Suwannee River to Apalachicola FL from 20 to 60 NM-Waters
from Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
NEAR TERM...Block/Lahr
SHORT TERM...Fournier
LONG TERM...Fournier
AVIATION...Harrigan
MARINE...Block/Lahr
FIRE WEATHER...Godsey
HYDROLOGY...Fournier/Block
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
652 PM CST Fri Nov 15 2013
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Saturday)
Issued at 250 PM CST FRI NOV 15 2013
On Friday afternoon, an upper trough was located over southern
California and Nevada while a series of weaker lead short wave
troughs were moving through fairly fast west southwest flow aloft
from the four counters into the western Plains. At the surface, low
pressure was deepening in eastern Colorado with intensifying
pressure gradient and southerly flow from southern Texas through the
Dakotas. A pool of quality low level moisture was in place across
northeast Texas and moving into eastern Oklahoma. As the lee surface
low continues to deepen overnight, expect a strong low level jet to
transport this moisture into eastern Kansas with a west to east
gradient while a strong elevated mixed layer and warm advection
builds above the moist boundary layer. The moist advection will
likely occur after a fairly quick evening cool down owing to mostly
clear skies, and the influx of moisture into cooler air along with
fairly strong ascent overnight and dry air aloft may contribute to
periods of drizzle during the early morning hours. There are also
some indications of moistening around 10 thousand feet which may
lead to weak elevated instability and at least some potential for a
few showers given the magnitude of lift. Winds at the surface will
also increase through the night as the pressure gradient strengthens.
Any light shower activity and drizzle will likely come to an end by
late Saturday morning as boundary layer mixing increases and
elevated capping increases. As mixing increases, the low level jet
will begin to mix gusts to the surface. The LLJ is forecast to have
50+ kt winds at 2500 feet AGL which would easily translate 45+ mph
wind gusts to the surface on a clear day, but the stratus deck may
be sufficient to limit overall mixing a bit, and by the time
clearing is forecast to occur, the LLJ will have weakened a bit. The
main question today is whether the depth of mixing will matter given
the strength of winds even 1500 feet AGL and the very strong late
morning pressure gradient. For now, have not issued a wind advisory,
but could certainly see the need to do so if future model guidance
suggests the 12Z NAM and recent RAP runs that highlight an even
stronger low level wind field. It`s a low confidence wind forecast
at this time that could result in peak gusts somewhere between 40
mph and 55 mph, with the strongest winds focused in east central KS.
By late afternoon, another lead short wave will approach the area.
At least partial afternoon clearing should have occurred with
temperatures in the lower 70s and dewpoints in the upper 50s. While
a strong capping inversion will be in place for much of the day, it
appears that the incoming trough will help cool the cap such that
afternoon CINH may decrease into the 10 to 50 J/KG range for a short
period between roughly 3 PM and 7 PM before rapidly increasing
again. Higher Res model guidance suggests MLCAPE in the 500 to 1000
J/KG range during this period while 0-6 km shear is 40 to 60 kts.
While these conditions would normally suggest some potential for a
few strong storms, the primary limiting factor...even with the
incoming short wave trough...is a general lack of any meaningful
surface convergence with the southwesterly low level wind field. The
lack of low level forcing along with a lopsided shear/CAPE balance
suggests it will be difficult to sustain any updrafts. At this time,
will maintain a slight chance of thunderstorms in the eastern parts
of KS generally east of Marysville to Burlington, and if one should
develop it would warrant an attentive eye.
.LONG TERM...(Saturday Night through Friday)
Issued at 250 PM CST FRI NOV 15 2013
By Saturday evening as the boundary layer begins to cool the
southwesterly low level jet increases which will ultimately
strengthen the capping inversion. The increasing low level jet
during the evening forces drier air into the lower levels. If an
elevated storm is able to form after sunset the dry air intrusion
should hinder any persistence. All of these factors should work
against any sustained storm threat across the area...therefore went
with a dry forecast after 00z Sun. Gusty winds continue for the
southeast half of the cwa and especially southeast of the turnpike
overnight Saturday into Sunday. Low temperatures range from the mid
40s in north central KS to the mid 50s in east central KS.
On Sunday morning the main upper level trough axis passes through
the region as well as the associated cold front. The cold front
should clear the area by 15z Sun with a significant drop in dew
points following the passage. Behind the main trough axis
northwesterly flow increases in response to the deepening pressure
field across the upper Midwest as the system becomes negatively
tilted. Forecast soundings show most locations mixing between 800 to
700 mb especially across central KS where dew points are lower. Red
flag criteria is possible Sunday during the day across the western
portions of the area with winds gusting to around 35 mph in
combination with the low relative humidity. Less certain is the
effect cooler air behind the front has on temperatures and how low
the dew points get Sunday afternoon determining min RH. Therefore
did not issue any headlines and will let later shifts evaluate the
latest guidance. High temperatures on Sunday look to reach the upper
50s to low 60s.
In the wake of that system dry northwest mid level flow sets up for
the central US allowing surface high pressure to build into the
region. Winds should begin to decrease Sunday evening with a
relatively calm day in store for Monday. The mid level flow quickly
transitions to a zonal pattern and return flow develops as the high
pressure retreats then the models really start to disagree by mid
week. The 12z ECMWF/GEM suggesting precip chances by Wed as a
shortwave pushes a front through the region, but this lacks any
consistency at this point therefore kept the forecast dry. Although
the better chances for precip appear to be on Thurs and Fri as a
trough approaches from the west coast. The evolution of that system
and the associated surface features is unknown. Have added the
possibility of snow Thurs night and Friday which is advertised by
the 12z ECMWF but confidence is pretty low. Through the extended
temperatures remain near average with highs in the 50s and lows in
the 30s with a cooling trend late in the period.
&&
.AVIATION...(For the 00Z TAFs through 00Z Saturday Evening)
Issued at 643 PM CST FRI NOV 15 2013
Expecting vfr conditions to give way to MVFR/IFR cigs in stratus
in the 06z-09z time frame (earlier at KTOP/KFOE) and persist
through 14z before scattering to vfr at KMHK with vfr conditions not
working into the KTOP/KFOE until 18z. With the degree of moisture
advection into the cool air...could see fog and some patchy
drizzle as well. Otherwise expect most precip to remain south and
east of the TAF sites through the fcst...with gusty south/southwest
winds of 20-30 gusts to 35kts slowly decreasing aft 22Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Sanders
AVIATION...63
AREA FORECAST DISCUSSION
NWS GOODLAND KS
158 PM MST THU NOV 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1251 PM MST THU NOV 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH ACROSS
WESTERN KS. SUBSIDENCE/DRYING ASSOCIATED WITH SHORTWAVE RIDGE
IMMEDIATELY BEHIND THE TROUGH AXIS IS SPREADING EAST OVER OUR CWA.
ANOTHER SHORTWAVE TROUGH IS IN PLACE ACROSS THE PAC NW WITH MID-HIGH
LEVEL MOISTURE PLUME OVER THE NORTHERN ROCKIES. AT THE SURFACE A
COLD FRONT THAT PUSHED ACROSS OUR CWA THIS MORNING IS NOW OVER
CENTRAL KANSAS EXTENDING SOUTH ACROSS THE TEXAS/OKLAHOMA PANHANDLES.
SURFACE HIGH PRESSURE IS IN PLACE ACROSS OUR CWA WITH CLEAR SKIES AND
SEASONAL TEMPS IN THE MID-UPPER 50S.
WITH DRY LAYER AND ONLY PASSING HIGH CLOUDS TO THE NORTH...THE
PRIMARY CONCERN IN THE SHORT TERM WILL BE POSSIBLE RFW CONDITIONS ON
FRIDAY AFTERNOON. AS SHORTWAVE RIDGE SHIFTS EAST AND UNIDIRECTIONAL
SW FLOW DEVELOPS ACROSS CWA WAA WILL BRING ABOVE NORMAL TEMPS BACK
TO OUR AREA...ALONG WITH DRY/WINDY CONDITIONS. I FOLLOWED THE
PREVIOUS FORECAST TREND AND BUMPED TEMPS UP A LITTLE FRIDAY
AFTERNOON...WITH WARMEST TEMPS LIKELY IN THE SOUTHERN PART OF OUR
CWA WHERE HIGHS AROUND 70F ARE LIKELY.
MODEL SOUNDINGS WOULD INDICATE GOOD MIXING HEIGHTS...SUPPORTING LOW
TD VALUES DURING THE AFTERNOON. I WAS CONSERVATIVE IN HOW LOW I
WENT...BUT STILL ENDED UP WITH TD VALUES IN THE TEENS ACROSS EASTERN
COLORADO. WARM TEMPS AND LOW DEWPOINTS WILL SUPPORT RH VALUES AT
LEAST IN THE 15-20 PERCENT RANGE...AND WITH GUSTY WINDS IT LOOKS
LIKE WE COULD SEE RFW CRITERIA MET AT LEAST ACROSS THE SW QUADRANT
OF OUR CWA. FURTHER NORTH AND EAST I AM NOT AS CONFIDENT IN MEETING
CRITERIA. IT IS HARD TO SAY IF WE WILL GET A FULL 3HR OF RFW
CRITERIA ACROSS THE SOUTHWEST SO I DECIDED TO START WITH A FIRE
WEATHER WATCH DURING THIS FORECAST CYCLE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 157 PM MST THU NOV 14 2013
INTI AL CONCERN FOR THE PERIOD WILL CENTER AROUND PRECIPITATION
CHANCES AS A SERIES OF LOW AMPLITUDE SHORT WAVE TROUGHS MOVE
AROUND THE BASE OF LARGE SCALE TROUGH THAT DIGS INTO THE AREA ON
SUNDAY. MODELS SEEM TO BE TRENDING DRIER AND DRIER WITH THESE
SYSTEMS AND WITH LATEST SREF AND GEFS DATA BACKING OFF OF POP
VALUES...THINK LOWERING POPS TO 10 PERCENT OR LESS WARRANTED AT
THIS TIME. AM CONCERNED ABOUT THE PERIOD OF STRONG FRONTAL SCALE
FORCING AND POTENTIAL INSTABILITY...BUT WITH DRY PROFILES AND
AFOREMENTIONED PROBABILISTIC FORECASTS...DO NOT THINK REALIZATION
OF INSTABILITY IS VERY LIKELY TO OCCUR.
OTHER CONCERN WILL BE POTENTIAL FOR STRONG WINDS DEVELOPING ACROSS
MUCH OF THE AREA ON SUNDAY. MODELS GENERALLY AGREE THAT TIGHT
HEIGHT GRADIENT WILL BE IN PLACE ACROSS THE AREA AS TROUGH SAGS TO
THE SOUTH...RESULTING IN STRONG WINDS JUST OFF THE SURFACE. AM NOT
EXPECTING WARNING LEVEL WINDS...BUT POTENTIAL APPEARS TO BE
INCREASING FOR ADVISORY TYPE WINDS IN THE AFTERNOON.
IN THE EXTENDED (SUN NIGHT-THURSDAY)...BRIEF PERIOD OF SHORT WAVE
RIDGING EXPECTED BEFORE A ZONAL/PROGRESSIVE PATTERN DEVELOPS ACROSS
THE AREA THROUGH THE REST OF THE WEEK. DOES NOT APPEAR TO BE MUCH
THREAT FOR PRECIPITATION DURING THIS PERIOD...WITH SOMEWHAT
PERSISTENT LEE TROUGH LEADING TO PREDOMINATELY WARM SOUTHERLY
FLOW. POTENTIAL FOR THICK MOUNTAIN CIRRUS DUE TO STRONG CROSS
MOUNTAIN FLOW LIMITS CONFIDENCE ON HOW WARM THINGS WILL GET...BUT
CONTINUED WARMING TREND LOOKS TO BE IN ORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1009 AM MST THU NOV 14 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK. GUSTY NORTHEAST WINDS IMMEDIATELY BEHIND COLD FRONT WILL
DIMINISH EARLY THIS AFTERNOON...WITH WINDS BECOMING LIGHT AND
VARIABLE AS HIGH PRESSURE DEVELOPS INTO THE PLAINS LATE THIS
AFTERNOON AND EARLY THIS EVENING AT BOTH TAF SITES. KMCK SHOULD
SEE WINDS DIMINISH FIRST WITH GRADIENT ALREADY BEGINNING TO RELAX.
WINDS WILL SHIFT TO THE SOUTH OVERNIGHT AS A SURFACE TROUGH
DEVELOPS IN EASTERN COLORADO. CURRENTLY EXPECT GUSTY SOUTHERLY
WINDS TO DEVELOP AT KGLD AROUND 14Z WITH GUSTS TO 30KT. WINDS
LIKELY WONT INCREASE AT KMCK UNTIL AFTER THE CURRENT TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR KSZ013-027-041.
CO...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR COZ253-254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1252 PM MST THU NOV 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1251 PM MST THU NOV 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH ACROSS
WESTERN KS. SUBSIDENCE/DRYING ASSOCIATED WITH SHORTWAVE RIDGE
IMMEDIATELY BEHIND THE TROUGH AXIS IS SPREADING EAST OVER OUR CWA.
ANOTHER SHORTWAVE TROUGH IS IN PLACE ACROSS THE PAC NW WITH MID-HIGH
LEVEL MOISTURE PLUME OVER THE NORTHERN ROCKIES. AT THE SURFACE A
COLD FRONT THAT PUSHED ACROSS OUR CWA THIS MORNING IS NOW OVER
CENTRAL KANSAS EXTENDING SOUTH ACROSS THE TEXAS/OKLAHOMA PANHANDLES.
SURFACE HIGH PRESSURE IS IN PLACE ACROSS OUR CWA WITH CLEAR SKIES AND
SEASONAL TEMPS IN THE MID-UPPER 50S.
WITH DRY LAYER AND ONLY PASSING HIGH CLOUDS TO THE NORTH...THE
PRIMARY CONCERN IN THE SHORT TERM WILL BE POSSIBLE RFW CONDITIONS ON
FRIDAY AFTERNOON. AS SHORTWAVE RIDGE SHIFTS EAST AND UNIDIRECTIONAL
SW FLOW DEVELOPS ACROSS CWA WAA WILL BRING ABOVE NORMAL TEMPS BACK
TO OUR AREA...ALONG WITH DRY/WINDY CONDITIONS. I FOLLOWED THE
PREVIOUS FORECAST TREND AND BUMPED TEMPS UP A LITTLE FRIDAY
AFTERNOON...WITH WARMEST TEMPS LIKELY IN THE SOUTHERN PART OF OUR
CWA WHERE HIGHS AROUND 70F ARE LIKELY.
MODEL SOUNDINGS WOULD INDICATE GOOD MIXING HEIGHTS...SUPPORTING LOW
TD VALUES DURING THE AFTERNOON. I WAS CONSERVATIVE IN HOW LOW I
WENT...BUT STILL ENDED UP WITH TD VALUES IN THE TEENS ACROSS EASTERN
COLORADO. WARM TEMPS AND LOW DEWPOINTS WILL SUPPORT RH VALUES AT
LEAST IN THE 15-20 PERCENT RANGE...AND WITH GUSTY WINDS IT LOOKS
LIKE WE COULD SEE RFW CRITERIA MET AT LEAST ACROSS THE SW QUADRANT
OF OUR CWA. FURTHER NORTH AND EAST I AM NOT AS CONFIDENT IN MEETING
CRITERIA. IT IS HARD TO SAY IF WE WILL GET A FULL 3HR OF RFW
CRITERIA ACROSS THE SOUTHWEST SO I DECIDED TO START WITH A FIRE
WEATHER WATCH DURING THIS FORECAST CYCLE.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 1146 PM MST WED NOV 13 2013
SHORTWAVE TROUGH AXIS WILL SWING THROUGH ON SUNDAY...BUT MODELS
CONTINUE TO TREND DOWNWARD WITH PRECIPITATION CHANCES. WILL NOT
REMOVE POPS ENTIRELY BUT WILL ONLY CARRY SLIGHT TO LOW CHANCE POPS
FOR RAIN OR RAIN/SNOW IN THE SUNDAY AND SUNDAY NIGHT PERIOD. THE
OTHER MAJOR MODEL TREND HAS BEEN TO BUILD A STRONGER RIDGE BEHIND
THAT SYSTEM WHICH WILL DOMINATE THE REMAINDER OF THE LONG TERM
PERIOD. WARMED UP TEMPERATURES AS MUCH AS ISC ALLOWED...PROBABLY
NOT ENOUGH...FOR THE MONDAY THROUGH THURSDAY PERIOD. NO
PRECIPITATION IS EXPECTED AFTER SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1009 AM MST THU NOV 14 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND
KMCK. GUSTY NORTHEAST WINDS IMMEDIATELY BEHIND COLD FRONT WILL
DIMINISH EARLY THIS AFTERNOON...WITH WINDS BECOMING LIGHT AND
VARIABLE AS HIGH PRESSURE DEVELOPS INTO THE PLAINS LATE THIS
AFTERNOON AND EARLY THIS EVENING AT BOTH TAF SITES. KMCK SHOULD
SEE WINDS DIMINISH FIRST WITH GRADIENT ALREADY BEGINNING TO RELAX.
WINDS WILL SHIFT TO THE SOUTH OVERNIGHT AS A SURFACE TROUGH
DEVELOPS IN EASTERN COLORADO. CURRENTLY EXPECT GUSTY SOUTHERLY
WINDS TO DEVELOP AT KGLD AROUND 14Z WITH GUSTS TO 30KT. WINDS
LIKELY WONT INCREASE AT KMCK UNTIL AFTER THE CURRENT TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR KSZ013-027-041.
CO...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR COZ253-254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1151 PM MST WED NOV 13 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1228 PM MST WED NOV 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE
RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH
ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH
IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN
TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV
IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS
THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE
UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE
SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN
COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY
LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES
REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO.
LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE
BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET.
THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH
THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH
ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN
PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE
BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY
MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE
FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT.
AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO
SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO
UPPER 50S.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 1146 PM MST WED NOV 13 2013
SHORTWAVE TROUGH AXIS WILL SWING THROUGH ON SUNDAY...BUT MODELS
CONTINUE TO TREND DOWNWARD WITH PRECIPITATION CHANCES. WILL NOT
REMOVE POPS ENTIRELY BUT WILL ONLY CARRY SLIGHT TO LOW CHANCE POPS
FOR RAIN OR RAIN/SNOW IN THE SUNDAY AND SUNDAY NIGHT PERIOD. THE
OTHER MAJOR MODEL TREND HAS BEEN TO BUILD A STRONGER RIDGE BEHIND
THAT SYSTEM WHICH WILL DOMINATE THE REMAINDER OF THE LONG TERM
PERIOD. WARMED UP TEMPERATURES AS MUCH AS ISC ALLOWED...PROBABLY
NOT ENOUGH...FOR THE MONDAY THROUGH THURSDAY PERIOD. NO
PRECIPITATION IS EXPECTED AFTER SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1025 PM MST WED NOV 13 2013
VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24
HOURS. SOUTHWEST WIND WILL SHIFT TO THE NORTHWEST OVERNIGHT AS A
SURFACE TROUGH SHIFTS EAST OF THE AREA AND HIGH PRESSURE FILTERS
IN BEHIND A COLD FRONT. WINDS WILL BE GUSTY AT TIMES ALONG AND
BEHIND THE FRONT AND THEN BECOME LIGHT BY THURSDAY
AFTERNOON/EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1029 PM MST WED NOV 13 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1228 PM MST WED NOV 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE
RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH
ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH
IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN
TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV
IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS
THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE
UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE
SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN
COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY
LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES
REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO.
LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE
BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET.
THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH
THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH
ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN
PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE
BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY
MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE
FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT.
AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO
SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO
UPPER 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 136 PM MST WED NOV 13 2013
THE MAIN LONG TERM FORECAST CONCERN IS STILL THE POSSIBILITY OF
PRECIPITATION BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT.
DRY CONDITIONS AND MID TEMPERATURES WITH PERIODIC INCREASES AND
DECREASES IN MOSTLY HIGH CLOUDS ARE EXPECTED FROM THURSDAY NIGHT
THROUGH SATURDAY AS A SERIES OF FRAGMENTED LEE TROUGHS ACCOMPANY A
SERIES OF UPPER SHORT WAVE TROUGHS ACROSS THE CENTRAL HIGH PLAINS
REGION.
BY SATURDAY NIGHT...THE MAIN UPPER TROUGH DIVES FROM THE PACIFIC
NORTHWEST INTO THE INTERMOUNTAIN REGION AND EMERGES EAST OF THE
ROCKIES ACROSS THE NORTHERN AND CENTRAL PLAINS ON SUNDAY. THE MAIN
FRONT MOVES THROUGH THE FORECAST AREA BY LATE SATURDAY WITH THE
COLDER AIR BEHIND THE FRONT TO MOVE INTO THE CENTRAL HIGH PLAINS
REGION SATURDAY NIGHT AND SUNDAY. CURRENTLY EXPECT A RAIN/SNOW MIX
TO MOVE INTO THE FORECAST AREA FROM THE NORTHWEST ON SATURDAY
NIGHT. THIS MIX WILL CHANGE OVER TO LIGHT RAIN DURING THE DAY ON
SUNDAY BEFORE CHANGING OVER TO LIGHT SNOW SUNDAY EVENING AS
PRECIPITATION ALSO BEGINS TO TAPER OFF FROM WEST TO EAST SUNDAY NIGHT.
DRY CONDITIONS ARE EXPECTED DURING THE FIRST PART OF NEXT WEEK
ALONG WITH COOLER THAN AVERAGE TEMPERATURES AS A SURFACE HIGH
PRESSURE AREA MOVES INTO THE PLAINS STATES WITH A RIDGE OF HIGHER
PRESSURE MOVING IN FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1025 PM MST WED NOV 13 2013
VFR CONDITIONS WILL CONTINUE FOR KGLD AND KMCK FOR THE NEXT 24
HOURS. SOUTHWEST WIND WILL SHIFT TO THE NORTHWEST OVERNIGHT AS A
SURFACE TROUGH SHIFTS EAST OF THE AREA AND HIGH PRESSSURE FILTERS
IN BEHIND A COLD FRONT. WINDS WILL BE GUSTY AT TIMES ALONG AND
BEHIND THE FRONT AND THEN BECOME LIGHT BY THURSDAY AFTERNOON/EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1113 PM CST Wed Nov 13 2013
.UPDATE...
Issued at 1113 PM CST WED NOV 13 2013
The latest RAP and NAM solutions show the pressure gradient
remaining up through the night across eastern KS. Because of this
and with recent OBS showing some gusts near 20 KTS, have updated
the min temps to bump them up due to continued mixing of the
boundary layer. There are two concerns. One is that I may not be
warm enough across east central KS where winds are most likely to
remain in the 10 to 15 MPH range overnight. The second is across
north central KS where the surface trough may move in just before
sunrise and allow the boundary layer to decouple and temps to
quickly drop off. However latest OBS across central NEB show that
temps have not be inclined to cool rapidly once the winds weaken,
possibly due to the increasing cloud cover from the approaching
upper wave. Because of this opted to keep lows at CNK (notorious
for keeping a wind through the night) in the middle 30s.
&&
.SHORT TERM...(This Evening through Thursday)
Issued at 249 PM CST WED NOV 13 2013
Little in the way of significant forecast problems for tonight and
Thursday. Sig pressure gradient between high over the southern
Mississippi valley and low pressure developing in the lee of the
Rockies has lead to gusty southerly winds today. These winds
will diminish late afternoon and early evening but maintain about 10
kts overnight...keeping temperatures from falling below the upper
20s to lower 30s.
Water vapor loop overlaid with RAP analysis and national radar show
precipitation associated with low amplitude shortwave trough
crossing the northern Rockies. This trough is forecast by all
models to move east across the northern U.S., approaching the
western Great Lakes by Thursday evening. Greatest forcing aloft and
any chance of measurable precipitation with this system is forecast
to stay well north of Kansas. Trailing surface low pressure trough
along with thicker mid and high level clouds should move into north
central and northeast Kansas Thursday afternoon. Thus...afternoon
winds on Thursday should not be as strong as those occurring today.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 249 PM CST WED NOV 13 2013
Focus of the longer term remains on the evolution of the storm
system into the weekend. Sfc low development will occur Friday
night into Saturday across western KS/NE as the first of two main
waves move through the longwave trough and into the plains. WAA
and lift should aid in the development of showers and perhaps
isolated thunderstorms later Friday night and into Saturday. Low
level winds veer in wake of the initial wave later Saturday
Saturday night so precip chcs appear sct at best during Sat night.
The second and main shortwave will emerge by Sunday along with the
associated sfc low. The low will track into Wisconsin later Sunday
with the cold front forecast to sweep through the area during the day.
The second upper wave remains progressive so don`t expect much in
the way of additional precip Sunday into Sunday night although CAA
along with shallow lift could result in light rain showers/drizzle
or some snow flurries later Sunday night.
All in all the ECMWF has trended less amplified with the pattern
into next week and as a result is not as cold while GFS remains
colder. In any case, it appears colder than avg for early next
week then moderating with dry/quiet weather after Sunday night.
&&
.AVIATION...(For the 06Z TAFs through 06Z Thursday Night)
Issued at 1113 PM CST WED NOV 13 2013
Limited moisture should allow for dry weather with VFR conditions
in spite of a weak upper level wave moving overhead late tonight
and Thursday. A surface trough axis is expected to remain west of
MHK so the forecast does not anticipate a wind shift prior to 06Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...GDP
LONG TERM...Omitt
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1003 PM EST FRI NOV 15 2013
.SYNOPSIS...
MILD WEATHER IS EXPECTED SATURDAY BEFORE A COLD FRONT CROSSES THE
REGION SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS WITH STRONG WINDS
WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT. COLD AIR RETURNS TO THE
AREA MID-WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SLGT ADJUSTMENTS MADE TO POP/WX GRIDS TO REFLECT ONGOING CVRG OF
SHWRS AND XPCD MVMT OF THESE SHWRS. NO SGFNT CHGS TO TIMING. PREV
DISCUSSION FOLLOWS...
PCPN IS BLOSSOMING ACRS SRN OH AND WV IN ASSOCIATION WITH SHRTWV
TROF EVIDENT OVER ERN KY BASED ON WATER VAPOR IMAGERY. THIS WAVE
WILL MOVE ENEWD ACRS SRN PORTIONS OF FCST AREA...WHERE PREV POPS
WERE FOCUSED. POPS WERE INCRD TO CATEGORICAL FOR LGT RAIN ACCUMS.
AS NOTED IN PREV FCST...CLDS WILL MAINTAIN ELEVATED MINIMA TNGT
WITH PSBL EXCEPTION OF FAR NRN ZONES...WHICH WILL DROP TO NR FRZG.
OTHERWISE...MID-UPR 30S WILL BE COMMON OVNGT.
H5 RDGG XPCD TO DOMINATE ON SAT. SOME MRNG LOW CLDS PSBL GIVEN
XPCD INCRG LOW-LVL MSTR RESULTING FROM SHRTWV TROF PASSAGE. MID-
AND UPR-LVL CLDS WILL LMT INSOLATION SOMEWHAT...WITH MAXIMA XPCD
TO REACH UPR 50S-NR 60 IN SVRL SPOTS. NO SGFNT WX XPCD ON SAT.
PREV DISCUSSION FOLLOWS...
A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES
WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY
SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW
LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM
PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES
BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN
TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER
TO MID 40S SOUTH.
SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING
ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE
SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
FLOW ALOFT WILL BCM SWLY AS UPR RDG SHIFTS EWD AND POTENT SHRTWV
TROF DIGS INTO THE NRN PLNS. IN RESPONSE TO DPNG SFC CYCLONE... H9
LOW-LVL JET OF 30-50 KT WILL ADVCT MSTR NWD AS FAR AS GRTLKS RGN.
MODELS SUGGEST A LEAD SHRTWV TROF WILL IMPACT THE FCST AREA SAT
NGT AND MAY GENERATE WDSPRD SHWRS FUELED BY THIS MSTR. WITH ALL
MODELS DEPICTING THIS SCENARIO...MAINTAINING DRY FCST DID NOT SEEM
PRUDENT. SO POPS WERE ADJUSTED CONSIDERABLY LATE SAT NGT AND SUN
MRNG.
CLD CVR WILL BE ABUNDANT SUN MRNG OWING TO PSBL ONGOING SHWRS. BUT
CVRG OF PCPN AND CLDS WILL WANE BY LATE SUN MRNG AS LEAD WAVE
EXITS. THUS...MODEST INSOLATION XPCD SUN AFTN WITH MAXIMA REACHING
MID TO UPR 60S. THERE MAY BE A LULL IN PCPN EARLY SUN AFTN AS
ATMOSPHERE RECOVERS.
BY LATE SUN AFTN...FORCING FOR ASCENT ASSOCIATED WITH THE PRIMARY
SHRTWV TROF WILL BGN TO SPREAD ACRS FCST AREA. SLGTLY UNSTABLE
ATMOSPHERE WILL BE WEAKLY-CAPPED...BUT SHEAR WILL BE EXTREME AND
LKLY WILL OVERCOME ANY DEFICIENCIES IN INSTBY.
PRIMARY FOCUS FOR SHWRS AND TSTMS WILL BE ALONG SFC TROF/EVENTUAL
CDFNT...WHICH WILL CROSS THE RGN SUN EVE. CELLULAR CNVCTN MAY DVLP
AHEAD OF THIS BNDRY...WITH STORM-RELATIVE INFLOW XPCD TO BE QUITE
RICH IN STREAMWISE VORTICITY GIVEN FCSTD HODOGRAPHS. AS A RESULT...
SCT LOW-TOPPED ROTATING TSTMS WILL BE PSBL LATE SUN AFTN-SUN EVE
BEFORE THE ARRIVAL OF THE CDFNT. THE POTL FOR THE PRE-FRONTAL
TSTMS IS CONDITIONAL UPON DVLPMT OF MODEST INSTBY IN WARM SECTOR.
WITH STRONG FORCING...WEAK INSTBY AND BULK SHEAR PARALLEL TO SFC
TROF...STORMS ALONG SFC TROF/CDFNT WILL BCM INCRGLY LINEAR THRU
SUN EVE. QUASI-LINEAR CNVCTV SYSTEM XPCD TO ENSUE AS THE BNDRY
MOVES EWD THRU THE EVE...AND WILL BE CAPABLE OF DMGG WIND GUSTS
AND QLCS MESOVORTEX TORNADOES. FCSTD SHEAR IS EXTREME...AND
HODOGRAPHS VERY FAVORABLE...FOR A SVR WX EPISODE LATE SUN AFTN
THRU SUN EVE.
ALL ZONES WILL SEE PCPN SUN NGT AS THE LINE CROSSES THE RGN. POPS
WERE INCRD TO 100 PCT WITH THE PASSAGE OF THE BNDRY. BNDRY XPCD
TO CLR THE FCST AREA BY MRNG WITH PSBLY CLR SKIES AT SUNRISE. PREV
DISCUSSION FOLLOWS...
MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF
A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND
HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL
APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH
SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS
THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY
AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF
HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE
FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS.
HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO.
FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE
DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE
WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS
TEMPERATURES RECOVER LITTLE FROM MORNING READINGS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS
INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT.
HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH
DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS
OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT
TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT
COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS
EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE
POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z.
VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH
AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL
THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG
HIGH PRES RTNS VFR CONDS LT TUE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
UPDATES...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
851 PM EST FRI NOV 15 2013
.SYNOPSIS...
MILD WEATHER IS EXPECTED SATURDAY BEFORE A COLD FRONT CROSSES THE
REGION SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS WITH STRONG WINDS
WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT. COLD AIR RETURNS TO THE
AREA MID-WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
PCPN IS BLOSSOMING ACRS SRN OH AND WV IN ASSOCIATION WITH SHRTWV
TROF EVIDENT OVER ERN KY BASED ON WATER VAPOR IMAGERY. THIS WAVE
WILL MOVE ENEWD ACRS SRN PORTIONS OF FCST AREA...WHERE PREV POPS
WERE FOCUSED. POPS WERE INCRD TO CATEGORICAL FOR LGT RAIN ACCUMS.
AS NOTED IN PREV FCST...CLDS WILL MAINTAIN ELEVATED MINIMA TNGT
WITH PSBL EXCEPTION OF FAR NRN ZONES...WHICH WILL DROP TO NR FRZG.
OTHERWISE...MID-UPR 30S WILL BE COMMON OVNGT.
H5 RDGG XPCD TO DOMINATE ON SAT. SOME MRNG LOW CLDS PSBL GIVEN
XPCD INCRG LOW-LVL MSTR RESULTING FROM SHRTWV TROF PASSAGE. MID-
AND UPR-LVL CLDS WILL LMT INSOLATION SOMEWHAT...WITH MAXIMA XPCD
TO REACH UPR 50S-NR 60 IN SVRL SPOTS. NO SGFNT WX XPCD ON SAT.
PREV DISCUSSION FOLLOWS...
A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES
WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY
SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW
LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM
PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES
BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN
TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER
TO MID 40S SOUTH.
SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING
ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE
SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
FLOW ALOFT WILL BCM SWLY AS UPR RDG SHIFTS EWD AND POTENT SHRTWV
TROF DIGS INTO THE NRN PLNS. IN RESPONSE TO DPNG SFC CYCLONE... H9
LOW-LVL JET OF 30-50 KT WILL ADVCT MSTR NWD AS FAR AS GRTLKS RGN.
MODELS SUGGEST A LEAD SHRTWV TROF WILL IMPACT THE FCST AREA SAT
NGT AND MAY GENERATE WDSPRD SHWRS FUELED BY THIS MSTR. WITH ALL
MODELS DEPICTING THIS SCENARIO...MAINTAINING DRY FCST DID NOT SEEM
PRUDENT. SO POPS WERE ADJUSTED CONSIDERABLY LATE SAT NGT AND SUN
MRNG.
CLD CVR WILL BE ABUNDANT SUN MRNG OWING TO PSBL ONGOING SHWRS. BUT
CVRG OF PCPN AND CLDS WILL WANE BY LATE SUN MRNG AS LEAD WAVE
EXITS. THUS...MODEST INSOLATION XPCD SUN AFTN WITH MAXIMA REACHING
MID TO UPR 60S. THERE MAY BE A LULL IN PCPN EARLY SUN AFTN AS
ATMOSPHERE RECOVERS.
BY LATE SUN AFTN...FORCING FOR ASCENT ASSOCIATED WITH THE PRIMARY
SHRTWV TROF WILL BGN TO SPREAD ACRS FCST AREA. SLGTLY UNSTABLE
ATMOSPHERE WILL BE WEAKLY-CAPPED...BUT SHEAR WILL BE EXTREME AND
LKLY WILL OVERCOME ANY DEFICIENCIES IN INSTBY.
PRIMARY FOCUS FOR SHWRS AND TSTMS WILL BE ALONG SFC TROF/EVENTUAL
CDFNT...WHICH WILL CROSS THE RGN SUN EVE. CELLULAR CNVCTN MAY DVLP
AHEAD OF THIS BNDRY...WITH STORM-RELATIVE INFLOW XPCD TO BE QUITE
RICH IN STREAMWISE VORTICITY GIVEN FCSTD HODOGRAPHS. AS A RESULT...
SCT LOW-TOPPED ROTATING TSTMS WILL BE PSBL LATE SUN AFTN-SUN EVE
BEFORE THE ARRIVAL OF THE CDFNT. THE POTL FOR THE PRE-FRONTAL
TSTMS IS CONDITIONAL UPON DVLPMT OF MODEST INSTBY IN WARM SECTOR.
WITH STRONG FORCING...WEAK INSTBY AND BULK SHEAR PARALLEL TO SFC
TROF...STORMS ALONG SFC TROF/CDFNT WILL BCM INCRGLY LINEAR THRU
SUN EVE. QUASI-LINEAR CNVCTV SYSTEM XPCD TO ENSUE AS THE BNDRY
MOVES EWD THRU THE EVE...AND WILL BE CAPABLE OF DMGG WIND GUSTS
AND QLCS MESOVORTEX TORNADOES. FCSTD SHEAR IS EXTREME...AND
HODOGRAPHS VERY FAVORABLE...FOR A SVR WX EPISODE LATE SUN AFTN
THRU SUN EVE.
ALL ZONES WILL SEE PCPN SUN NGT AS THE LINE CROSSES THE RGN. POPS
WERE INCRD TO 100 PCT WITH THE PASSAGE OF THE BNDRY. BNDRY XPCD
TO CLR THE FCST AREA BY MRNG WITH PSBLY CLR SKIES AT SUNRISE. PREV
DISCUSSION FOLLOWS...
MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF
A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND
HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL
APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH
SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS
THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY
AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF
HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE
FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS.
HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO.
FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE
DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE
WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS
TEMPERATURES RECOVER LITTLE FROM MORNING READINGS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS
INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT.
HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH
DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS
OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT
TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT
COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS
EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE
POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z.
VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH
AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL
THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG
HIGH PRES RTNS VFR CONDS LT TUE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
655 PM EST FRI NOV 15 2013
.SYNOPSIS...
A MILD WEEKEND IS IN STORE AFTER A WEAK WEATHER SYSTEM BRINGS
CLOUDS...AND A FEW SHOWERS MAINLY SOUTH AND EAST OF PITTSBURGH
TONIGHT. A POWERFUL COLD FRONT WILL BRING SHOWERS AND STRONG WINDS
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
A SOUTHERN STREAM SHORTWAVE MOVING ACROSS THE MID ATLANTIC STATES
WILL INCREASE CLOUDS THIS EVENING...WITH SHOWERS DEVELOPING MAINLY
SOUTH OF I-70 AND IN THE FAR SOUTHEAST RIDGES OVERNIGHT. DRY LOW
LEVELS WILL LIMIT RAINFALL AMOUNTS BUT KEPT THE LIKELY POPS FROM
PREVIOUS FORECAST ACROSS GARRETT...TUCKER...AND PRESTON COUNTIES
BUT WILL BE A HIGH POP LOW QPF EVENT. WITH CLOUDS MOVING IN
TEMPERATURES WILL BE HELD UP IN THE UPPER 30S FAR NORTH TO LOWER
TO MID 40S SOUTH.
SYSTEM WILL QUICKLY EXIT SATURDAY WITH SOUTHWEST FLOW DEVELOPING
ALOFT AND TEMPERATURES WARMING INTO THE 50S AND OVER 60 ACROSS THE
SOUTH ALONG WITH AT LEAST PARTLY SUNNY SKIES.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MILD SATURDAY NIGHT AS CLOUDS AND DEEP MOISTURE INCREASE AHEAD OF
A STRONG STORM SYSTEM DEVELOPING ACROSS THE NORTHERN PLAINS AND
HEADING INTO THE NORTHERN GREAT LAKES SUNDAY. COLD FRONT WILL
APPROACH THE REGION BY LATE DAY SUNDAY AND CROSS SUNDAY NIGHT WITH
SHOWERS AND POSSIBLE THUNDERSTORMS. SHOWERS WILL BE INCREASING AS
THE DAY PROGRESSES SUNDAY WITH SOUTH WINDS GUSTING OVER 30 MPH BY
AFTERNOON. SYSTEM SUNDAY NIGHT LOOKS TO BE REMINISCENT OF
HALLOWEEN COLD FRONT WITH A POSSIBLE CONVECTIVE LINE ALONG THE
FRONT BRINGING DOWN WINDS FROM A LOW LEVEL JET APPROACHING 70KTS.
HAVE HIGHLIGHTED THE POTENTIAL FOR DAMAGING WINDS IN THE HWO.
FRONT EXITS EAST BY SUNRISE MONDAY WITH COLD ADVECTION DURING THE
DAY. COLDEST AIR LAGS THE FRONT SO A DRY PERIOD EARLY WILL GIVE
WAY TO SOME LAKE ENHANCED SHOWERS AND UPSLOPE BY AFTERNOON AS
TEMPERATURES RECOVER LITTLE FROM MORNING READINGS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AN UPR TROF COMBINED WITH NW FLOW ACRS THE GT LKS WL CONT PCPN CHCS
INTO TUE. WITH COLD AIR ADVCTN ANY RAIN SHOULD CHG TO SNW MON NGT.
HIGH PRES AND WRM AIR ADVCTN SHOULD END ANY PCPN BY LT TUE...WITH
DRY WEA AND SLOWLY WRMG TEMPS CONTG THRU THE END OF THE WK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS
OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT
TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT
COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS
EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE
POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z.
VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH
AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL
THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG
HIGH PRES RTNS VFR CONDS LT TUE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
528 AM CST THU NOV 14 2013
.UPDATE...
ISSUED AT 523 AM CST THU NOV 14 2013
UPDATED TO INCLUDE 12Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST THU NOV 14 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOWING
POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING FROM MANITOBA SOUTHWEST
INTO WYOMING. THIS FEATURE IS MOVING EAST QUICKLY... AND WILL HELP
PUSH A COLD FRONT THROUGH THE AREA TODAY. MID-HIGH CLOUDS HAVE
BLOSSOMED ALONG/AHEAD OF THE UPPER WAVE AND FRONTAL BOUNDARY... WITH
SOME PCPN OCCURRING UP AROUND 8-10K FT AGL OR SO. THERE IS SOME PCPN
REACHING THE GROUND OVER SOUTHWEST SOUTH DAKOTA... BUT OVERALL
THINGS ARE VIRGA GIVEN THE DRY ANTECEDENT AIRMASS WHICH WAS QUITE
APPARENT ON THE KMPX... KABR... AND KOAX 00Z SOUNDINGS. AS THIS
SYSTEM PROGRESSES EAST TODAY IT MAY EVENTUALLY MANAGE TO GET SOME
PCPN TO THE GROUND. THE 03Z HOPWRF KEEPS MOST OF THE ACTIVITY
ALOFT... BUT SUGGEST SOME LIGHT PCPN COULD OCCUR OVER THE FAR
SOUTH/EAST PORTIONS OF THE FORECAST AREA THIS MORNING. THE GFS IS
THE MOST AMBITIOUS IN GENERATING SOME PCPN... BUT THE ECMWF ALSO
PRODUCES SOME. FORCING IS DECENT... WITH A BAND OF DPVA AND SOME
UPPER DIVERGENCE... BUT MOISTURE IS THE OBVIOUS MISSING COMPONENT.
THE THALER QG DIAGNOSTICS SWING THROUGH MOST OF THE FORCING THIS
MORNING... WITH SUBSIDENCE QUICKLY WORKING IN THIS AFTERNOON.
SIMPLEST THING TO DO IS TO STAY CLOSE TO THE GOING FORECAST... WHICH
INCLUDED SOME LOW CHANCE POPS OVER THE SOUTH/EAST PORTION OF THE
AREA THIS MORNING. WILL ALSO MAINTAIN A FEW SMALL POCKETS OF
FREEZING PCPN CHANCES EARLY THIS MORNING IN CASE IN PCPN OCCURS
WHILE SURFACE TEMPERATURES ARE STILL AOB FREEZING... SINCE CURRENT
OBS OVER WEST CENTRAL WISCONSIN SUGGEST SOME LOCAL READINGS ARE DOWN
IN THAT AREA. OTHERWISE... WE/LL SEE SLIGHTLY COOLER AIR ARRIVE
BEHIND THE FRONT FOR TONIGHT... BUT WILL BE RIGHT BACK INTO RETURN
FLOW BY FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 AM CST THU NOV 14 2013
THE MAIN CONCERN IN THE LONGER TERM IS THE PROGRESSION OF THE
UPPER TROUGH OVER THE WESTERN U.S. ON FRIDAY TO THE GREAT LAKES BY
MONDAY. THE GFS SOLUTION REMAINS THE OUTLIER WITH BASICALLY ONE
TROUGH MOVING THROUGH DURING THE WEEKEND. THIS WOULD DRIVE A LOW
PRESSURE SYSTEM NORTHEAST ACROSS MN/WI ON SATURDAY/SATURDAY NIGHT
WITH A COLD FRONT SWEEPING THROUGH EARLY ON SUNDAY. THE ECWMF AND
GEM ARE MORE CONSISTENT WITH THE TROUGH MOVING THROUGH IN TWO
PARTS. ONE PIECE OF ENERGY MOVES THROUGH ON SATURDAY WITH THE
MAIN TROUGH MOVING THROUGH SUNDAY/SUNDAY NIGHT. THIS YIELDS AN
AREA OF LOW PRESSURE MOVING ACROSS MN/WI SATURDAY/SATURDAY NIGHT
WITH RAIN LIKELY IN MOST AREAS...ESPECIALLY EASTERN MN/WI. A
SECOND LOW THEN RIDES NORTHEAST FROM THE CENTRAL PLAINS TO EASTERN
WI FROM SATURDAY NIGHT TO SUNDAY NIGHT. THE LOW/MID LEVEL THERMAL
PROFILE FROM THE ECMWF IS TOO WARM FOR MUCH SNOW AT THIS TIME IN
MN WITH SOME POTENTIAL FOR ACCUMULATING SNOW IN WESTERN WI SUNDAY
NIGHT. THE PROBLEM IS THAT THE COLD AIR IS MOVING IN ABOUT AS FAST
AS THE MOISTURE IS LEAVING... SO THERE IS ONLY A SMALL WINDOW OF
OPPORTUNITY.
IT WILL CERTAINLY TURN WINDY AND COLDER IN THE WAKE OF THE LOW
SUNDAY NIGHT AND MONDAY. THE DROP IN HIGHS FROM SUNDAY TO MONDAY
STILL LOOKS TO BE ON THE ORDER OF 15 DEGREES OR SO. HIGH PRESSURE
MOVES QUICKLY ACROSS THE UPPER MISSISSIPPI VALLEY MONDAY NIGHT
WITH A WARMING TREND DEVELOPING ON TUESDAY AND LASTING INTO THE
LATTER HALF OF THE WORK WEEK. THE HIGHS FOR TUESDAY AND WEDNESDAY
WILL LIKELY NEED TO BE RAISED BY A CATEGORY OR MORE IF THE ECMWF
SOLUTION FOR EARLY NEXT WEEK IS MORE ON TARGET THEN THE REST. IN
FACT THE ECMX MOS INDICATES MIDDLE 40S FOR TUESDAY AND WEDNESDAY.
THE PATTERN DEVELOPING EARLY NEXT WEEK LOOKS MUCH LIKE YESTERDAY
(WEDNESDAY). THE MAIN CULPRIT DRAGGING DOWN THE CR EXTEND HIGHS
WAS DGEX WITH HIGHS IN THE TEENS AND 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 523 AM CST THU NOV 14 2013
A WEAK SHORTWAVE AND COLD FRONT WILL MOVE THROUGH THE AREA
TODAY... BRINGING MAINLY MID-HIGH CLOUDS. SOME CEILINGS AOA 5K FT
AGL COULD OCCUR FOR A SHORT TIME ALONG WITH SOME SPRINKLES... BUT
THAT SHOULD BE THE EXTENT OF THINGS. WINDS WILL VEER AS THE FRONT
MOVES THROUGH... THEN BEGIN TO BACK AGAIN TOWARD THE END OF THE
FORECAST PERIOD AS RETURN FLOW SETS BACK UP OVER THE REGION. THERE
COULD BE SOME PATCHY FOG LATE TONIGHT... BUT AT THIS POINT IT
APPEARS THAT THERE COULD BE ENOUGH CLOUD COVER AROUND TO KEEP IT
FROM HAPPENING. HOWEVER... THAT IS SOMETHING THAT WILL NEED TO BE
WATCHED IN SUBSEQUENT FORECASTS.
KMSP...TAF REFLECTS EXPECTATIONS WITH MINIMAL UNCERTAINTY. THERE
COULD BE SLIGHTLY LOWER CEILINGS FOR A SHORT TIME TODAY... BUT
THEY WOULD STILL BE VFR. THERE COULD ALSO BE SOME MVFR FOG LATE
TONIGHT... BUT CONFIDENCE IS TOO LOW AT THIS POINT TO INCLUDE IN
THE TAF.
/OUTLOOK FOR KMSP/
FRIDAY AFTERNOON...VFR. SOUTH WIND 5 TO 15 KT.
FRIDAY NIGHT...MVFR CEILINGS EXPECTED LATE. IFR CEILINGS AND MVFR
VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN. SOUTHEAST WIND 10 TO
20 KT.
SATURDAY...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR
POSSIBLE. SOUTHEAST WIND 15 TO 20 KT.
SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN...
IFR POSSIBLE. SOUTH WIND 10 TO 20 KT BECOMING SOUTHWEST.
SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
RAIN/SNOW... IFR POSSIBLE EARLY. WEST WIND 10 TO 20 KT BECOMING
NORTHWEST 15 TO 25 KT.
SUNDAY NIGHT...MVFR CEILINGS POSSIBLE EARLY. NORTHWEST WIND 10 TO
20 KT.
MONDAY...VFR. NORTHWEST WIND 5 TO 15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...
LONG TERM...RAH
AVIATION...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
334 AM CST THU NOV 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST THU NOV 14 2013
LATEST WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSES SHOWING
POSITIVELY TILTED SHORTWAVE TROUGH EXTENDING FROM MANITOBA SOUTHWEST
INTO WYOMING. THIS FEATURE IS MOVING EAST QUICKLY... AND WILL HELP
PUSH A COLD FRONT THROUGH THE AREA TODAY. MID-HIGH CLOUDS HAVE
BLOSSOMED ALONG/AHEAD OF THE UPPER WAVE AND FRONTAL BOUNDARY... WITH
SOME PCPN OCCURRING UP AROUND 8-10K FT AGL OR SO. THERE IS SOME PCPN
REACHING THE GROUND OVER SOUTHWEST SOUTH DAKOTA... BUT OVERALL
THINGS ARE VIRGA GIVEN THE DRY ANTECEDENT AIRMASS WHICH WAS QUITE
APPARENT ON THE KMPX... KABR... AND KOAX 00Z SOUNDINGS. AS THIS
SYSTEM PROGRESSES EAST TODAY IT MAY EVENTUALLY MANAGE TO GET SOME
PCPN TO THE GROUND. THE 03Z HOPWRF KEEPS MOST OF THE ACTIVITY
ALOFT... BUT SUGGEST SOME LIGHT PCPN COULD OCCUR OVER THE FAR
SOUTH/EAST PORTIONS OF THE FORECAST AREA THIS MORNING. THE GFS IS
THE MOST AMBITIOUS IN GENERATING SOME PCPN... BUT THE ECMWF ALSO
PRODUCES SOME. FORCING IS DECENT... WITH A BAND OF DPVA AND SOME
UPPER DIVERGENCE... BUT MOISTURE IS THE OBVIOUS MISSING COMPONENT.
THE THALER QG DIAGNOSTICS SWING THROUGH MOST OF THE FORCING THIS
MORNING... WITH SUBSIDENCE QUICKLY WORKING IN THIS AFTERNOON.
SIMPLEST THING TO DO IS TO STAY CLOSE TO THE GOING FORECAST... WHICH
INCLUDED SOME LOW CHANCE POPS OVER THE SOUTH/EAST PORTION OF THE
AREA THIS MORNING. WILL ALSO MAINTAIN A FEW SMALL POCKETS OF
FREEZING PCPN CHANCES EARLY THIS MORNING IN CASE IN PCPN OCCURS
WHILE SURFACE TEMPERATURES ARE STILL AOB FREEZING... SINCE CURRENT
OBS OVER WEST CENTRAL WISCONSIN SUGGEST SOME LOCAL READINGS ARE DOWN
IN THAT AREA. OTHERWISE... WE/LL SEE SLIGHTLY COOLER AIR ARRIVE
BEHIND THE FRONT FOR TONIGHT... BUT WILL BE RIGHT BACK INTO RETURN
FLOW BY FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 AM CST THU NOV 14 2013
THE MAIN CONCERN IN THE LONGER TERM IS THE PROGRESSION OF THE
UPPER TROUGH OVER THE WESTERN U.S. ON FRIDAY TO THE GREAT LAKES BY
MONDAY. THE GFS SOLUTION REMAINS THE OUTLIER WITH BASICALLY ONE
TROUGH MOVING THROUGH DURING THE WEEKEND. THIS WOULD DRIVE A LOW
PRESSURE SYSTEM NORTHEAST ACROSS MN/WI ON SATURDAY/SATURDAY NIGHT
WITH A COLD FRONT SWEEPING THROUGH EARLY ON SUNDAY. THE ECWMF AND
GEM ARE MORE CONSISTENT WITH THE TROUGH MOVING THROUGH IN TWO
PARTS. ONE PIECE OF ENERGY MOVES THROUGH ON SATURDAY WITH THE
MAIN TROUGH MOVING THROUGH SUNDAY/SUNDAY NIGHT. THIS YIELDS AN
AREA OF LOW PRESSURE MOVING ACROSS MN/WI SATURDAY/SATURDAY NIGHT
WITH RAIN LIKELY IN MOST AREAS...ESPECIALLY EASTERN MN/WI. A
SECOND LOW THEN RIDES NORTHEAST FROM THE CENTRAL PLAINS TO EASTERN
WI FROM SATURDAY NIGHT TO SUNDAY NIGHT. THE LOW/MID LEVEL THERMAL
PROFILE FROM THE ECMWF IS TOO WARM FOR MUCH SNOW AT THIS TIME IN
MN WITH SOME POTENTIAL FOR ACCUMULATING SNOW IN WESTERN WI SUNDAY
NIGHT. THE PROBLEM IS THAT THE COLD AIR IS MOVING IN ABOUT AS FAST
AS THE MOISTURE IS LEAVING... SO THERE IS ONLY A SMALL WINDOW OF
OPPORTUNITY.
IT WILL CERTAINLY TURN WINDY AND COLDER IN THE WAKE OF THE LOW
SUNDAY NIGHT AND MONDAY. THE DROP IN HIGHS FROM SUNDAY TO MONDAY
STILL LOOKS TO BE ON THE ORDER OF 15 DEGREES OR SO. HIGH PRESSURE
MOVES QUICKLY ACROSS THE UPPER MISSISSIPPI VALLEY MONDAY NIGHT
WITH A WARMING TREND DEVELOPING ON TUESDAY AND LASTING INTO THE
LATTER HALF OF THE WORK WEEK. THE HIGHS FOR TUESDAY AND WEDNESDAY
WILL LIKELY NEED TO BE RAISED BY A CATEGORY OR MORE IF THE ECMWF
SOLUTION FOR EARLY NEXT WEEK IS MORE ON TARGET THEN THE REST. IN
FACT THE ECMX MOS INDICATES MIDDLE 40S FOR TUESDAY AND WEDNESDAY.
THE PATTERN DEVELOPING EARLY NEXT WEEK LOOKS MUCH LIKE YESTERDAY
(WEDNESDAY). THE MAIN CULPRIT DRAGGING DOWN THE CR EXTEND HIGHS
WAS DGEX WITH HIGHS IN THE TEENS AND 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1111 PM CST WED NOV 13 2013
COLD FRONT OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE
FORECAST PERIOD AS AN UPPER LEVEL DISTURBANCE TRACK ALONG THE
US/CANADIAN BORDER. MID-HIGH CLOUDS CONTINUE TO EXPAND ALONG/AHEAD
OF THESE FEATURES... AND WE SHOULD SEE THEM OVERSPREAD THE AREA
OVERNIGHT. SOME LOWER CEILINGS... PERHAPS AOB 5K FT AGL OVER THE
EASTERN PORTION OF THE AREA... WILL OCCUR FROM AROUND12-17Z... AND
THE FAR EAST/SOUTHEAST COULD SEE SOME LIGHT PCPN AS WELL.
HOWEVER... THINGS WILL GENERALLY BE VFR WITH FAIRLY LIGHT WINDS
VEERING THROUGH THE PERIOD.
KMSP...TAF REFLECTS EXPECTATIONS WITH MINIMAL UNCERTAINTY. THE
ONLY REAL QUESTION WOULD BE WHETHER SOME LOWER CEILINGS MANIFEST
THEMSELVES THURSDAY MORNING... BUT AT THIS POINT THAT APPEARS TO
BE A LOW PROBABILITY OF OCCURRENCE AND WOULD STILL BE VFR.
/OUTLOOK FOR KMSP/
FRIDAY...VFR. SOUTH WIND 5 TO 15 KT.
FRIDAY NIGHT...MVFR CEILINGS EXPECTED LATE. IFR CEILINGS AND MVFR
VISIBILITIES POSSIBLE WITH A CHANCE OF RAIN. SOUTHEAST WIND 10 TO
20 KT.
SATURDAY...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN... IFR
POSSIBLE. SOUTHEAST WIND 15 TO 20 KT.
SATURDAY NIGHT...MVFR CEILINGS AND VISIBILITIES EXPECTED WITH RAIN...
IFR POSSIBLE. SOUTH WIND 10 TO 20 KT BECOMING SOUTHWEST.
SUNDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
RAIN/SNOW... IFR POSSIBLE EARLY. WEST WIND 10 TO 20 KT BECOMING
NORTHWEST 15 TO 25 KT.
SUNDAY NIGHT...MVFR CEILINGS POSSIBLE EARLY. NORTHWEST WIND 10 TO
20 KT.
MONDAY...VFR. NORTHWEST WIND 5 TO 15 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...RAH
AVIATION...LRS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1123 PM CST WED NOV 13 2013
.UPDATE...
ISSUED AT 1124 PM CST WED NOV 13 2013
UPDATE FOR THE AVIATION DISCUSSION BELOW...
UPDATE ISSUED AT 836 PM CST WED NOV 13 2013
PARTS OF THE FORECAST WERE UPDATED THROUGH THURSDAY. THE FOCUS IS
ON THE CLOUD COVER AND PCPN CHANCES/TYPE.
THERE ARE SCT/BKN HIGH CLOUDS MOVING ACROSS THE NORTHLAND THIS
EVENING AS AN ILL DEFINED TROUGH MOVES THROUGH THE REGION. THESE
CLOUDS SHOULD CONTINUE TO SPREAD ACROSS THE FORECAST AREA THROUGH
TONIGHT. THE CLOUD COVER AND LIGHT SW TO W WINDS SHOULD HELP
BOLSTER TEMPERATURES JUST A TAD...SO I RAISED THE LOW TEMPERATURE
FORECAST JUST A BIT IN SPOTS.
I HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF LOW CLOUDS AND/OR
FOG LATE TONIGHT AND IN THE MORNING BEFORE THE BOUNDARY LAYER
MIXES OUT LATER IN THE MORNING. MODEL SOUNDINGS ARE SUGGESTING A
SATURATED BOUNDARY LAYER WILL DEVELOP LATE TONIGHT.
HOWEVER...THERE IS A RELATIVELY DEEP DRY LAYER ABOVE THE BOUNDARY
LAYER...AND THE LIGHT SW TO W FLOW AND ITS MIXING MAY BE ENOUGH TO
PREVENT LOW CLOUDS AND/OR FOG FROM FORMING. THEREFORE...I
REFRAINED FROM DRAMATICALLY INCREASING CLOUD COVER TONIGHT AND
TOMORROW MORNING AND DID NOT ADD FOG INTO THE FORECAST...BUT THIS
IS SOMETHING THE NIGHT SHIFT WILL NEED TO REEVALUATE.
THERE SHOULD BE INCREASING CLOUDS FROM THE NORTH LATE TONIGHT.
THERE IS ALREADY A LARGE AREA OF LOW CLOUDS ACROSS MUCH SOUTH
CENTRAL CANADA...SO I EXPECT THE CLOUDS TO BEGIN TO ROLL INTO THE
BORDERLAND LATE TONIGHT. THERE WILL BE INCREASING PCPN CHANCES
FROM THE NORTH TOMORROW MORNING. I SLIGHTLY ALTERED THE PCPN TYPE
FORECAST SO THAT IT BEGINS AS SNOW THROUGH THE MORNING...AND THEN
A MIX OF RAIN AND SNOW IN THE AFTERNOON. THE PREVIOUS FORECAST HAD
RAIN IN THE LATE MORNING AND AFTERNOON...BUT SOUNDINGS AND SURFACE
TEMPERATURES APPEAR TO SUPPORT AT LEAST SOME SNOW DURING THE
AFTERNOON. THERE SHOULD BE LITTLE TO NO ACCUMULATION.
SEVERAL MODELS ARE SUGGESTING THERE MAY BE A BAND OF PCPN ACROSS
THE FAR SE FORECAST AREA LATE TONIGHT OR TOMORROW MORNING. MOST
OF THE MODELS SUGGEST IT WILL BE MID TO LATE MORNING...BUT THE GFS
AND HRRR SUGGEST IT MAY BE EARLIER. THIS PCPN WILL BE ASSOCIATED
WITH THE CLOUDS AROUND 10 KFT CURRENTLY MOVING ACROSS THE FORECAST
AREA. I SUSPECT IT WILL BEGIN AS VIRGA BECAUSE OF THE DRY LAYER
UNDERNEATH THE CLOUD DECK. HOWEVER...WE WILL NEED TO MONITOR THIS
EARLIER POTENTIAL FOR PCPN BECAUSE IF IT MANAGES TO REACH THE
GROUND...THEN THERE COULD BE A SHORT WINDOW OF LIGHT FREEZING
RAIN. IF IT HOLDS OFF TILL LATER IN THE MORNING...THE PCPN SHOULD
BE RAIN.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM CST WED NOV 13 2013
A COUPLE OF WEAK SFC TROFS WERE WORKING THEIR WAY THROUGH THE
CENTRAL AND EASTERN PORTIONS OF THE FA AT 19Z. MEANWHILE...A WARM
FRONT WAS MOVING INTO THE WESTERN EDGE OF THE FA AND A COLD FRONT
ENTERING THE RED RIVER VALLEY. THE MAIN IMPACTS WITH THESE FEATURES
HAS BEEN WIND SHIFTS AND WARMER AIR BEHIND THE WARM FRONT AS SEEN IN
SFC OBS WITH TEMPS AROUND 50F IN NW MN. TEMPS BEHIND THE COLD FRONT
HAD REACHED THE LOWER 50S DUE TO COMPRESSIONAL WARMING. A GUSTY SW
SFC WIND COVERED THE AREA AHEAD OF THE FRONTS ALONG WITH SOME CI
CLOUDS.
THE WARM FRONT WILL FALL APART AS IT MOVES THROUGH THE FA THIS
EVENING. THE COLD FRONT WILL DISSIPATE AS IT REACHES THE WESTERN
EDGE OF THE FA AND REFORM FURTHER S IN WEST CENTRAL MN. EVEN WITH
ALL THIS FRONTAL ACTIVITY...NO PCPN IS EXPECTED TONIGHT DUE TO A
LACK OF DEEP MOISTURE AND FORCING. CLOUDS HOWEVER WILL BE ON THE
INCREASE AND KEEP MIN TEMPS IN THE UPPER 20S TO LOWER 30S.
ON THURSDAY...ANOTHER COLD FRONT IS FORECAST TO DEVELOP IN SOUTHERN
CANADA AND REACH THE INTERNATIONAL BORDER BY 18Z. A LONG WAVE TROF
MOVES INTO MN AS WELL. THERE IS A BIT MORE MOISTURE AVAILABLE. THIS
WILL AFFORD A SMALL POP OVER SOUTHERN PRICE COUNTY IN WI FOR LIGHT
RAIN IN THE VCNTY OF A SFC TROF. LOW CHANCE POPS IN THE VCNTY OF THE
COLD FRONT. PTYPE WILL START AS ALL SNOW NEAR THE CANADIAN BORDER
WITH A MIX OF RAIN AND SNOW BY MID MORNING THURSDAY BEFORE
TRANSITIONING TO ALL RAIN BY AFTERNOON. AMOUNTS WILL BE LIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM CST WED NOV 13 2013
A WARM SOUTHERLY FLOW SETS UP ACROSS THE UPPER MIDWEST
FRIDAY/SATURDAY AS A LONG WAVE TROUGH DEEPENS OVER THE ROCKIES. THE
NORTHLAND BECOMES SITUATED INT HE WARM SLOT AHEAD OF THE TOUGH
SATURDAY. THERE IS GOOD MODEL AGREEMENT THAT A SURGE OF MOISTURE
LIFTS INTO THE GREAT LAKES REGION FRIDAY NIGHT/SATURDAY WITH PWATS
RAPIDLY INCREASING INTO THE 0.6-0.8" RANGE. HAVE KEPT LIKELY POPS
FOR RAIN OVER THE EASTERN ZONES...WHILE THERE REMAINS SOME
UNCERTAINTY IN THE WESTWARD EXTENT OF THE PRECIP SAT. BASED ON NAM
BUFR SOUNDINGS AND MID-LVL TEMP PROFILES HAVE PTYPE REMAINING ALL
RAIN FRIDAY NIGHT THROUGH SATURDAY. THERE IS A VERY MINIMAL THREAT
FOR -FZDZ IF THE SFC TEMPS FALL BELOW FREEZING...BUT CLOUD TOP TEMPS
REMAIN WELL ABOVE FREEZING AND LIMIT ANY ICE GROWTH.
FOCUS TURNS TO CYCLOGENESIS OVER THE CENTRAL PLAINS SATURDAY NIGHT.
THE 12Z RUNS OF THE GFS/ECM CONTINUE TO HAVE RUN TO RUN VARIABILITY
IN THE STORM TRACK AND TIMING. HOWEVER...THERE IS AGREEMENT THAT THE
H85 TROUGH DEEPENS INTO A CLOSED LOW AS IT LIFTS OVER
MINNESOTA/WISCONSIN DURING THE SATURDAY NIGHT/SUNDAY TIME FRAME. AS
EXPECTED...THE GFS REMAINS THE FASTER OF THE TWO SOLUTIONS BY A GOOD
12HR. THE GFS SUGGESTS THE H85 LOW CENTER TRACKS ACROSS THE MN
ARROWHEAD EARLY SUNDAY MORNING...WHILE THE ECM BRINGS THE H85 LOW
OVER NRN WISCONSIN SUNDAY AFTERNOON. THE DIFFERENCE IN STORM TRACK
WILL DETERMINE THE RAIN/SNOW TRANSITION ZONE AND SNOWFALL AMOUNTS
ASSOCIATED WITH THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1124 PM CST WED NOV 13 2013
LIGHT SW TO W WINDS ARE EXPECTED ACROSS NE MINNESOTA AND NW
WISCONSIN THROUGH THURSDAY. THE VFR CONDITIONS ACROSS THE REGION
SHOULD CONTINUE THROUGH THE NIGHT...BUT THERE IS A VERY LOW
POSSIBILITY OF IFR/MFVR CIGS DEVELOPING LATE TONIGHT.
OTHERWISE...MVFR CIGS AND/OR VFR CIGS IN THE 3 TO 5 KFT RANGE WILL
BEGIN TO DEVELOP THURSDAY MORNING. THERE MAY BE SOME -SN AND -RA
ACROSS NORTHERN MINNESOTA...INCLUDING KINL AND KHIB...LATE
THURSDAY MORNING AND THROUGH THURSDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 31 42 30 41 / 0 10 10 10
INL 27 35 26 38 / 10 30 30 10
BRD 30 44 29 44 / 0 10 10 20
HYR 28 43 29 44 / 10 10 10 10
ASX 32 43 31 44 / 0 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LSZ140>142.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...GRANING
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
351 PM CST Thu Nov 14 2013
.SHORT TERM: (Through Late Tonight)
Issued at 348 PM CST Thu Nov 14 2013
A dry air mass with low dew points will promote efficient cooling
tonight, however WAA and mid/high clouds will temper the drop-off and
keep overnight lows in the mid 30s.
Kanofsky
.LONG TERM: (Friday through Next Thursday)
Issued at 348 PM CST Thu Nov 14 2013
A weak disturbance was located over central NM around 21z per water
vapor imagery and recent RAP 1.5 PVU analyses. This feature will
quickly swing through TX tonight before reaching AR and MS tomorrow.
Although the air mass over MO/IL remains fairly dry, a few sprinkles
or light rain showers are possible over the eastern Ozarks on Fri
morning before this vort max lifts away from the area.
Look for a continued warming trend through the weekend due to
persistent southwest surface flow along with warming temperatures
aloft. Highs will probably reach the mid to upper 70s on Sun despite
substantial cloud cover and periods of precipitation. High
temperatures will fall back into the 30s and 40s early next week
after a strong cold front moves across the region on Sunday
afternoon and evening.
Wind speeds will increase on Fri night as the pressure gradient
tightens between the surface high over the southeast US and the
developing low pressure system over the plains. Expect breezy
conditions through Sun with the highest wind speeds and gusts on
Sat.
Two low pressure systems are expected to affect our area this
weekend. The first vort max was located near the WA coast around 18z
this afternoon and is forecast to reach KS by Sat. The LLJ induced
by this feature will interact with a lifting warm front to produce
an area of rain on late Fri night and Sat morning. PW values are
forecast to rise to around 1.2" by Sat, which is around +2 SD for
November, so plenty of moisture will be available. There will
probably be a break in the rain sometime on Sat aftn between
systems. A stronger vort max is forecast to cross the Rockies and
induce surface cyclogenesis along the pre-existing baroclinic zone
over OK/KS on Sat night. Instability and lift ahead of this system
should support an area of rain showers with embedded thunderstorms.
The attendant cold front then moves through the CWA on Sun aftn/eve
as the system lifts towards the Great Lakes and begins to occlude.
With substantial shear in place along with at least some
instability, there is a potential for severe thunderstorms on Sun
ahead of the advancing cold front. Although there are some timing
differences between models, most of the latest model runs bring the
cold front through the LSX CWA before 00z Mon. Such timing would
limit the severe weather threat across our area to the far eastern
CWA at most. If future model runs support a slower fropa, then there
may be more of a concern for severe thunderstorms.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1132 AM CST Thu Nov 14 2013
Primary weather concern this afternoon will be south to southwest
winds that will occasionally gust into the 20-25 kt range...mainly
over the northwest half of the CWA. These winds will diminish
heading into the early evening hours, and ramping up of low level
jet may cause some LLWS concerns after 03z. Progged low level
winds from NAM are just a bit below LLWS criteria but it will be
close, and evening shift will need to keep an eye on this. While
any cloudiness through this evening will be limited to cirrus,
lower level moisture return on Friday morning should mean a
gradual lowering of cigs but attm it appears cloud bases will
remain aoa 5kft.
Specifics for KSTL: Winds of 200-210 degrees will occasionally
gust to around 20 kts this afternoon, with surface winds backing a
bit and rapidly diminishing into the 8-10kt range by early this
evening. As mentioned in primary AFD will need to keep an eye on
LLWS potential later this evening and overnight, as winds at the
1500-2000 agl are progged to increase into the 35-40kt range.
Cloudiness through 06z will be aoa 10kft.
Truett
&&
.CLIMATE:
Issued at 348 PM CST Thu Nov 14 2013
Record highs for Sunday, November 17th
STL 78 1958
COU 78 1958
UIN 78 1952
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
338 PM CST Thu Nov 14 2013
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Thu Nov 14 2013
A dry air mass with low dew points will promote efficient cooling
tonight, however WAA and mid/high clouds will temper the drop-off and
keep overnight lows in the mid 30s.
Kanofsky
.LONG TERM: (Friday through Next Thursday)
Issued at 336 PM CST Thu Nov 14 2013
A weak disturbance was located over central NM around 21z per water
vapor imagery and recent RAP 1.5 PVU analyses. This feature will
quickly swing through TX tonight before reaching AR and MS tomorrow.
Although the air mass over MO/IL remains fairly dry, a few sprinkles
or light rain showers are possible over the eastern Ozarks on Fri
morning before this vort max lifts away from the area.
Look for a continued warming trend through the weekend due to
persistent southwest surface flow along with warming temperatures
aloft. Highs will probably reach the mid to upper 70s on Sun despite
substantial cloud cover and periods of precipitation. High
temperatures will fall back into the 30s and 40s early next week
after a strong cold front moves across the region on Sunday
afternoon and evening.
Wind speeds will increase on Fri night as the pressure gradient
tightens between the surface high over the southeast US and the
developing low pressure system over the plains. Expect breezy
conditions through Sun with the highest wind speeds and gusts on
Sat.
Two low pressure systems are expected to affect our area this
weekend. The first vort max was located near the WA coast around 18z
this afternoon and is forecast to reach KS by Sat. The LLJ induced
by this feature will interact with a lifting warm front to produce
an area of rain on late Fri night and Sat morning. PW values are
forecast to rise to around 1.2" by Sat, which is around +2 SD for
November, so plenty of moisture will be available. There will
probably be a break in the rain sometime on Sat aftn between
systems. A stronger vort max is forecast to cross the Rockies and
induce surface cyclogenesis along the pre-existing baroclinic zone
over OK/KS on Sat night. Instability and lift ahead of this system
should support an area of rain showers with embedded thunderstorms.
The attendant cold front then moves through the CWA on Sun aftn/eve
as the system lifts towards the Great Lakes and begins to occlude.
With substantial shear in place along with at least some
instability, there is a potential for severe thunderstorms on Sun
ahead of the advancing cold front. Although there are some timing
differences between models, most of the latest model runs bring the
cold front through the LSX CWA before 00z Mon. Such timing would
limit the severe weather threat across our area to the far eastern
CWA at most. If future model runs support a slower fropa, then there
may be more of a concern for severe thunderstorms.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1132 AM CST Thu Nov 14 2013
Primary weather concern this afternoon will be south to southwest
winds that will occasionally gust into the 20-25 kt range...mainly
over the northwest half of the CWA. These winds will diminish
heading into the early evening hours, and ramping up of low level
jet may cause some LLWS concerns after 03z. Progged low level
winds from NAM are just a bit below LLWS criteria but it will be
close, and evening shift will need to keep an eye on this. While
any cloudiness through this evening will be limited to cirrus,
lower level moisture return on Friday morning should mean a
gradual lowering of cigs but attm it appears cloud bases will
remain aoa 5kft.
Specifics for KSTL: Winds of 200-210 degrees will occasionally
gust to around 20 kts this afternoon, with surface winds backing a
bit and rapidly diminishing into the 8-10kt range by early this
evening. As mentioned in primary AFD will need to keep an eye on
LLWS potential later this evening and overnight, as winds at the
1500-2000 agl are progged to increase into the 35-40kt range.
Cloudiness through 06z will be aoa 10kft.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
337 AM CST THU NOV 14 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CST THU NOV 14 2013
MODELS IN FAIR AGREEMENT IN THE NEAR TERM. UPPER TROUGH MOVING
EAST ACROSS THE FORECAST AREA TODAY WITH HIGH BASED SHOWERS OVER
NORTHWEST NEBRASKA SLIDING EAST. CHADRON HAS REPORTED
LIGHT PRECIPITATION FOR A WHILE BUT PINE RIDGE JUST STARTED. WILL
RETAIN SPRINKLES ACROSS NORTHERN ZONES THROUGH MID MORNING WITH
EASTERLY MOVEMENT AROUND 20KTS. TEMPERATURES HOLDING UP WITH CLOUD
COVER THIS MORNING. NORTHERLY WINDS STARTING TO INCREASE OVER THE
NORTHERN PANHANDLE AND THIS WILL TRANSLATE EAST THROUGH THE DAY.
HIGHS SOME TEN DEGREES COOLER TODAY. CLEARING SKIES TONIGHT AND
LIGHT SOUTHERLY FLOW LOW TEMPERATURES FALLING TO AROUND 30.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 337 AM CST THU NOV 14 2013
MODELS CONTINUE TO SHOW TROUGH DIGGING ACROSS THE WEST FRIDAY AND
QUICKLY TRANSITIONING EAST TO THE GREAT LAKES BY MONDAY. AT THE
SFC A COUPLE OF LOW PRESSURE SYSTEMS WILL MOVE ACROSS THE PLAINS.
THE FIRST LOW IS EXPECT TO LIFT NE ACROSS THE CENTRAL PLAINS
SATURDAY. TRACK STILL UNCERTAIN AS MODELS CONTINUE TO WOBBLE AS IT
LIFTS ACROSS PORTIONS OF KS/NEB. MODEL CONSENSUS IS TO LIFT IT
QUICKLY ACROSS NW KS/S CENTRAL THEN E NEBRASKA. RAIN/THUNDER LOOKS
GOOD TO THE EAST OF THE CWA...HOWEVER LIMITED MOISTURE AND WARM BL
LOOKS TO KEEP THE OUR PART OF NEB DRY. MODELS HAVE EVEN CUT BACK
ON RH PERCENTAGES ALOFT WITH MAV GUIDANCE EVEN SHOWING SCT
SKIES. THUS THINK THERE COULD BE SOME PEAKS OF SUN AND TRENDED
WITH GUIDANCE AND RAISED TEMPS.
SATURDAY NIGHT/SUNDAY A COLD FRONT WILL PUSH ACROSS THE AREA.
TEMPS NOTICEABLY COOLER SUNDAY...ESPECIALLY ACROSS THE NW AS THE
COLD AIR ARRIVES EARLY WITH HIGHS LIKELY IN THE MORNING. PRECIP
CHANCES SPREAD TO THE SOUTH AS THE COLD AIR CONTINUES TO FILL IN
BEHIND THE FRONT. SOUNDING PROFILES COOL QUICKLY WITH RAIN TO
CHANCE TO SNOW DURING THE DAY/EVENING FROM NW TO SE. THE HOLD OUT
FOR CHANGE OVER TO SNOW WILL BE SURF TEMPS AS THEY WARM INTO THE
40S AHEAD OF THE FRONT AND WILL TAKE SOME TIME TO COOL DURING THE
DAYLIGHT HOURS. GROWING CONCERN ABOUT PRECIP CHANCES...AS MODELS
ARE FASTER WITH THE UPPER TROUGH AND THE JET SUPPORT IS QUICKER TO
PUSH EAST. MODELS IN AGREEMENT IN REDUCING QPF AMOUNTS...AND MOS
GUIDANCE HAS REDUCED POPS. DO EXPECT AT LEAST CLOUDS AND SOME
LIGHT PRECIP...ALTHOUGH NOT LOOKING AS IMPRESSIVE AS COUPLE OF
DAYS AGO...WILL CONTINUE TO MONITOR.
THE BIGGEST CHANGE FROM PREVIOUS RUNS OCCURS NEXT WEEK. THE FASTER
PROGRESSION OF THE SYSTEM ALLOWS WARMER AIR TO RETURN QUICKLY TO
THE HIGH PLAINS. A COUPLE DAYS AGO 850 MB TEMPS BOTTOMED OUT IN
THE -10 TO -15 DEGREE C RANGE MONDAY MORNING WITH A SLOW
REBOUND...HOWEVER NOW THEY BARELY FALL BELOW ZERO DEGREES C.
GUIDANCE FOLLOWS SUIT WITH MONDAY AND TUESDAY SOME 5 TO 15 DEGREES
WARMER FROM THE 12Z RUN FOR HIGHS. CLEARING SKIES AND HIGH
PRESSURE OVERHEAD SUNDAY NIGHT SHOULD STILL ALLOW FOR LOWS IN THE
TEENS...HOWEVER TEMPS ARE ABLE TO REBOUND QUICKLY...WELL INTO THE
40S AND EVEN 50S POSSIBLE AS EARLY AS MONDAY. THE 00Z EC HAS
ARRIVED WITH THE WARMEST CONDITIONS WITH GUIDANCE SUGGESTION HIGHS
COULD NEAR 60 BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CST WED NOV 13 2013
THE LATEST RAP AND NAM MODEL SOLNS SUGGEST AN AREA OF MVFR CIGS
MAY DEVELOP ALONG AND WEST OF HIGHWAY 61 FROM KOGA NORTH BETWEEN
06Z AND 12Z. IT ALSO LOOKS LIKE SCATTERED LIGHT SHOWERS WILL MOVE
THROUGH NRN NEB OVERNIGHT...PERHAPS AS FAR EAST AS KVTN. SOME
SOLNS LIKE THE GFS AND HRRR MODELS CARRY THE SHOWERS THROUGH KONL.
GIVEN THE DRY AIR AT THE LOWER LEVELS...THIS MIGHT BE A STRETCH
BUT SPRINKLES ARE POSSIBLE IN THAT AREA.
OTHERWISE VFR IS EXPECTED ALL AREAS FROM 12Z ON THROUGH 06Z
THURSDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...POWER
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1130 PM CST WED NOV 13 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CST WED NOV 13 2013
A WEAK UPPER LEVEL DISTURBANCE WILL TRACK SOUTHEAST FROM NORTHWEST
WYOMING INTO WESTERN NEBRASKA OVERNIGHT. WILL CONTINUE THE SLIGHT
CHANCE FOR SHOWERS AS THIS DISTURBANCE MOVES ACROSS...BUT DRY AIR IN
THE MID LEVELS OF THE ATMOSPHERE WILL KEEP ANY PRECIPITATION
ISOLATED THAT MANAGES TO REACH THE GROUND. OTHERWISE A WEAK COLD
FRONT WILL PUSH SOUTHEAST...WITH TEMPERATURES ACTUALLY RISING AFTER
THE FRONTAL PASSAGE AS WARMER AIR ALOFT IS MIXED TO THE SURFACE.
LOWS ACROSS NORTHERN NEBRASKA WILL BE VERY MILD...NEAR 40 DEGREES. A
LITTLE COOLER FARTHER SOUTH AHEAD OF THE FRONT...WHERE CALM WINDS
WILL ALLOW FOR TEMPERATURES TO DROP INTO THE LOWER AND MID 30S
AROUND MIDNIGHT...BUT THEN RISE TO UPPER 30S AFTER THE FRONT PASSES
AND WIND INCREASES.
ANOTHER MILD DAY EXPECTED THURSDAY...BUT NOT QUITE AS WARM AS TODAY.
TEMPERATURES ALOFT WILL COOL SOME...AND NOT MUCH MIXING EXPECTED
WITH LIGHT WINDS. HIGHS IN THE LOWER TO MID 50S LOOK GOOD FOR MOST
LOCALS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CST WED NOV 13 2013
THE GFS40..GEMNH...NAM12 AND THE 00Z ECMWF SHOW GOOD AGREEMENT WITH
THE CYCLOGENESIS OVER COLORADO FRIDAY AND FRIDAY NIGHT AND WITH THE
TRACK OF THE SYSTEM. A CROSS-SECTION FROM ONEILL TO HOLDREGE SHOWS
SOME ISENTROPIC UPGLIDE AHEAD OF THE SYSTEM IN THE 300-310K LAYER.
THE LIFTED PARCELS ARE NOWHERE NEAR SATURATED...SO ACTUAL
PRECIPITATION AMOUNTS WILL BE LIMITED. IN FACT...FORECAST SOUNDINGS
IN THE AREA INDICATE A SHALLOW LAYER OF SUPER-COOLED SATURATED AIR
AND WEAK LIFT THAT IS MORE INDICATIVE OF DRIZZLE. WITH SURFACE
TEMPERATURES OF 30F...ANY THAT DOES FALL WILL PROBABLY FREEZE ON
SURFACES.
THERE ARE STILL SIGNIFICANT DIFFERENCES AMONG THE MODELS WITH THE
SYSTEM EARLY NEXT WEEK...SO THE UNCERTAINTY REMAINS HIGH. THERE IS A
TIMING DIFFERENCE BETWEEN THE GFS40 AND THE GEMNH OF ABOUT 6 HOURS.
THE 12Z ECMWF IS A LITTLE SLOWER YET. OTHERWISE...THEY ARE SHOWING A
SIMILAR PATTERN WITH AN OPEN UPPER WAVE CROSSING THE CENTRAL AND
NORTHERN PLAINS AT LEAST UNTIL THE SYSTEM MOVES INTO THE UPPER
MISSISSIPPI VALLEY.
AN ARCTIC FRONT IS EXPECTED TO CROSS NEBRASKA SUNDAY AND SUNDAY
NIGHT. LOOKING AT A CROSS SECTION FROM ABOUT GILLETTE WYOMING TO
NEAR EMPORIA KANSAS AND FROM VALENTINE TO MCCOOK...THE COMBINATION
OF SYSTEM-RELATIVE ISENTROPIC LIFT IN THE 290-300K LAYER AND
INSTABILITY INDICATED BY FOLDED THETA-E WILL GENERATE STRONG UPWARD
MOTION. MODERATE MOISTURE IS AVAILABLE WITH SPECIFIC HUMIDITY IN
THAT LAYER OF 1-3G/KG. HOWEVER...THE SYSTEM IS A QUICK HIT
AND...BECAUSE IT WILL BE ONLY ABOUT EIGHT HOURS DURATION...THE
PRECIPITATION AMOUNTS WILL BE LIMITED. IN FACT...THE QPF OF
0.07-0.12 INDICATED BY THE GFS SEEMS REASONABLE. THERE IS ENOUGH
LIFT AND MOISTURE IN THE DENDRITIC LAYER THAT SNOW PRODUCTION SHOULD
BE EFFICIENT. A FORECAST SOUNDING FOR NORTH PLATTE...WHICH IS ABOUT
THE MIDDLE OF THE MAXIMUM UPWARD MOTION...SHOWS A FAIRLY WARM LAYER
BELOW 725MB WITH THE WET BULB ZERO NEAR 820MB. THAT SHOULD RESULT IN
FAIRLY RAPID COOLING AND LIGHT RAIN CHANGING OVER TO SNOW.
ACCUMULATIONS WILL NOT BE HEAVY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1130 PM CST WED NOV 13 2013
THE LATEST RAP AND NAM MODEL SOLNS SUGGEST AN AREA OF MVFR CIGS
MAY DEVELOP ALONG AND WEST OF HIGHWAY 61 FROM KOGA NORTH BETWEEN
06Z AND 12Z. IT ALSO LOOKS LIKE SCATTERED LIGHT SHOWERS WILL MOVE
THROUGH NRN NEB OVERNIGHT...PERHAPS AS FAR EAST AS KVTN. SOME
SOLNS LIKE THE GFS AND HRRR MODELS CARRY THE SHOWERS THROUGH KONL.
GIVEN THE DRY AIR AT THE LOWER LEVELS...THIS MIGHT BE A STRETCH
BUT SPRINKLES ARE POSSIBLE IN THAT AREA.
OTHERWISE VFR IS EXPECTED ALL AREAS FROM 12Z ON THROUGH 06Z
THURSDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1239 AM EST THU NOV 14 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL SLIDE OFF TO THE SOUTH ALLOWING A
WEST TO SOUTHWEST FLOW TO DEVELOP AND GRADUALLY BRING MILDER AIR BACK
INTO THE REGION TONIGHT THROUGH THIS WEEKEND. IT WILL BE MAINLY
DRY WITH THE NEXT CHANCE OF SIGNIFICANT PRECIPITATION EARLY NEXT
WEEK IN THE FORM OF RAIN SHOWERS.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 946 PM EST WEDNESDAY...LOW-LEVEL WARM AIR ADVECTION REGIME
UNDERWAY ACROSS THE NORTH COUNTRY WITH INCREASING SOUTH/SOUTHWEST
SFC WINDS. INITIAL AREA OF OVERCAST SKIES EARLIER THIS EVENING HAS
SINCE SHIFTED EASTWARD WITH INFRARED SATELLITE AND OBSERVATIONS
INDICATING THAT UPSTREAM CLOUDINESS IS MAINLY AT MID-LEVELS.
THOUGH CLOUDINESS IS BEGINNING TO THIN OUT...STILL BELIEVE THAT
LOW TEMPS HAVE ALREADY BEEN REACHED IN MANY AREAS AS STRENGTHENING
WIND FIELDS WILL HELP KEEP BOUNDARY LAYER WELL MIXED AND WITH LOW
LEVELS WARMING. TEMPS WILL THEN CONTINUE TO FOLLOW A NON-DIURNAL
TREND WITH TEMPS HOVERING OR SLIGHTLY RISING FROM CURRENT READINGS
THROUGH THE REST OF THE EVENING.
I`VE REMOVED THE SLIGHT CHANCE/CHANCE POPS ACROSS THE ADIRONDACKS
AND SAINT LAWRENCE VALLEY. SOME QUESTION AS TO HOW MUCH LAKE
EFFECT CAN TAKE PLACE AS RECENT HRRR RUNS HAVE BECOME LESS BULLISH
ON ITS POTENTIAL. THERE`S FAVORABLE TRAJECTORIES FOR LAKE MOISTURE
ADVECTION AND I COULD SEE SOME ENHANCEMENT IN CLOUDINESS THERE.
HOWEVER WITH MODEL SOUNDINGS SHOWING AN UNSATURATED ICE NUCLEI
LAYER...IF ANYTHING WERE TO FALL OUT OF ANY LAKE EFFECT CLOUDS IT
MAY NOT AMOUNT TO MUCH MORE THAN LIGHT DRIZZLE. SO I`VE OPTED TO
SIDE WITH THE HRRR AND REMOVE MENTION OF ANY SNOW SHOWERS FOR THIS
EVENING.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 330 PM EST WEDNESDAY...DRY AND FAIR WEATHER WILL CONTINUE
FROM THURSDAY THROUGH FRIDAY NIGHT AS SURFACE HIGH REMAINS THE
MAIN WEATHER FEATURE ACROSS THE NORTH COUNTRY. TEMPERATURES WILL
WARM INTO THE UPPER 30S TO MID 40S TOMORROW WITH SOUTHERLY FLOW IN
PLACE ACROSS THE AREA USHERING IN SOME MILDER AIR. TEMPS THURSDAY
NIGHT WILL BE EVEN WARMER THAN TONIGHT WITH WARM AIR ADVECTION
CONTINUING ON SOUTHERLY FLOW. THE WARMING TREND WILL CONTINUE FOR
FRIDAY AND FRIDAY NIGHT WITH EACH PERIOD A FEW DEGREES WARMER THAN
THE PREVIOUS DAYS MAX AND MIN TEMPS. THERE WILL BE SOME CLOUDS
AROUND DUE TO WEAK SHORTWAVES CROSSING THE REGION DURING THE SHORT
TERM.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...FOR THE EXTENDED PERIOD...MUCH OF THE
UPCOMING WEEKEND OVER THE ENTIRE CWA WILL HAVE ABV NORMAL
CONDITIONS...AS HIGH PRESSURE SITS OFFSHORE TO OUR EAST AND LOW
PRESSURE W/ ASSOCIATED STRONG CD FRONT RESIDES OVER THE GREAT
LKS/MIDWEST REGION. THIS WILL KEEP THE REGION UNDER STRONG WAA ON
SSW FLOW. 925MB TEMPS INCR FROM 0C TO +4C ON SATURDAY TO +8C TO
+10C ON SUNDAY AS GRADIENT INCR AHEAD OF FRONT. AS A
RESULT...LOOKING FOR SUNDAY TO BE THE WARMER OF THE 2-DAY PERIOD
W/ HIGHS RAMPING UP FROM THE UPPER 40S/LOWS 50S TO THE 50S TO NEAR
60F IN SPOTS SUNDAY IN MANY SPOTS. TEMPS SUNDAY WILL BE CLD COVER
DEPENDENT AS FRONT APPROACHES FOR N NY. MDLS IN FAIR CONSENSUS
THAT FRONT WILL BE SLOW TO PUSH THRU REGION SUN NGT/MON DUE TO
BLOCKING RIDGE OFFSHORE. AS A RESULT...CVLY WESTWARD WILL HAVE
CHANCE FOR 50S FOR HIGHS BFR CD AIR BEHIND FRONT ARRIVES. STRONG
JET DYNAMICS AHEAD OF FRONT FROM 925MB TO 700MB COULD BRING SFC
WIND GUSTS NEAR 30-40MPH. W/ FRONT TAPPING INTO GULF
MOISTURE...MDL QPF COULD BRING 0.50-1.00" RAINFALL AMTS. AS FRONT
PASSES THRU AREA SUNDAY NGT/MONDAY...COLDER AIR ON INCR WNW FLOW
BEHIND SYSTEM WILL BRING CHANGEOVER FROM -RW TO -SW AT HIR ELEV
FIRST....THEN GOING INTO TUESDAY/WEDNESDAY WITH ENTIRE CWA
SLIPPING FROM NEAR TO BLW NORMAL TEMPS...-SW FOR ALL AREAS WITH
HIGHEST POPS ON HIR TRRN/NW FACING SLOPES.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THROUGH 06Z FRIDAY...AVIATION CHALLENGE WL BE LOW CIGS AT SLK THIS
MORNING AND WINDS. SFC ANALYSIS SHOWS TIGHT PRES GRADIENT ACRS OUR
TAF SITES CREATING BREEZY SOUTHWEST SFC WINDS. THIS WL CONT FOR
MOST OF THE DAY WITH GUSTS BTWN 15 AND 25 KNOTS EXPECTED. IN
ADDITION...THIS SOUTHWEST FLW WL HELP ADVECT LOW LEVEL LAKE
ENHANCED MOISTURE IN SLK TODAY...WITH SOME LOWER CIGS ANTICIPATED.
WL MENTION MVFR CIGS...BUT COULD SEE A BRIEF PERIOD OF IFR CIGS
WITH AREAS OF BR/-DZ BTWN 10-16Z TODAY...BEFORE DRIER AIR
DEVELOPS. OTHERWISE...SCATTERED TO BROKEN CIGS WL SLOWLY BECM
MOSTLY CLR THIS AFTN...WITH SOUTHWEST WINDS.
OUTLOOK 06Z FRIDAY THROUGH MONDAY...
SFC HIGH PRES WL RESULT IN VFR CONDITIONS FOR FRIDAY WITH MAINLY
LIGHT TRRN DRIVEN WINDS. SOME INCREASE IN CLOUDS ASSOCIATED WITH
SEVERAL WEAK DISTURBANCES IN THE WINDS ALOFT WL BE POSSIBLE ON
FRIDAY NIGHT INTO SATURDAY...BUT VFR CONDITIONS SHOULD PREVAIL.
NEXT SYSTEM WL IMPACT REGION LATE SUNDAY INTO MONDAY WITH A PERIOD
OF RAIN SHOWERS LIKELY AND MVFR CONDITIONS. IN ADDITION...VERY
GUSTY SOUTHERLY WINDS BTWN 30 AND 40 KNOTS WL BE POSSIBLE AHEAD OF
SFC COLD FRNT. THIS WL CREATE AREAS OF LLVL WS AND
TURBULENCE...ESPECIALLY ACRS THE HIGHER TRRN AND OPEN VALLEY
TERMINALS. A WIND SHIFT TO THE WEST WL OCCUR BY MONDAY
NIGHT...WITH IMPROVING CONDITIONS.
&&
.MARINE...
WINDS SHIFT INTO THE SSW ACROSS LAKE CHAMPLAIN THIS EVENING...AND
WILL INCREASE TO 15-25 KNOTS AFTER MIDNIGHT. THE HIGHEST WINDS AND
WAVES - BUILDING TO 2-4 FEET - WILL BE ACROSS THE NORTHERN END OF
THE BROAD LAKE TOWARD THE SOUTHERN PORTION OF GRAND ISLE. A LAKE
WIND ADVISORY HAS BEEN POSTED FOR CONDITIONS EXPECTED AFTER
MIDNIGHT. WINDS WILL SUBSIDE SLIGHTLY BY LATE MORNING
THURSDAY...BUT LIKELY REMAIN S-SW 10-20 KNOTS THROUGH MOST OF THE
DAYLIGHT HOURS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SISSON
NEAR TERM...NEILES/LOCONTO
SHORT TERM...NEILES
LONG TERM...JN
AVIATION...TABER
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
949 PM EST FRI NOV 15 2013
.SYNOPSIS...
A WARM FRONT AND COASTAL TROUGH WILL BRING SHOWERS TONIGHT. ABOVE
NORMAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND WITH THE RISK
FOR SHOWERS INCREASING AGAIN LATE SUNDAY INTO MONDAY AS A COLD
FRONT APPROACHES FROM THE WEST. THE FRONT WILL CROSS THE AREA
MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER CONDITIONS
THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 930 PM FRIDAY...I`VE GOT TO SAY...THIS FORECAST ISN`T WORKING
OUT LIKE I HAD HOPED. THE 00Z CHARLESTON SOUNDING SHOWS PRECIPITABLE
WATER HAS RISEN TO NEARLY 1.3 INCHES...BUT ALSO SHOWS SEVERAL
3000-5000 FT THICK DRY LAYERS LOCATED RIGHT IN THE ZONE I WOULD
EXPECT THE BEST ISENTROPIC LIFT TO BE OCCURRING. THE 00Z NAM
INITIALIZED QUITE WELL VERSUS THE CHARLESTON THERMAL/MOISTURE
PROFILE AND HAS REALLY TONED DOWN ITS RAINFALL POTENTIAL THROUGH
12Z. THE 18Z GFS WAS FAR TOO WET AND SHOWS TOO MUCH MOISTURE
THROUGHOUT THE 700-400 MB LAYER VERSUS THE CHARLESTON SOUNDING. THE
LATEST HRRR ALSO IS NOT CAPTURING TRENDS WELL AND IS BEING IGNORED.
CHANGES WITH THIS UPDATE INCLUDE CUTTING POPS BACK TO 40-50 PERCENT
FOR THE REMAINDER OF THE NIGHT AND SLASHING QPF FORECASTS TO AROUND
0.05 INCHES. WHILE THE LOCATION AND DEGREE OF ISENTROPIC LIFT HAS
PROBABLY BEEN WELL-FORECAST BY THE MODELS ALL ALONG...DRY LIFT
DOESN`T YIELD RAINFALL. BREAKS HAVE EVEN OPENED IN THE OVERCAST DECK
NEAR GEORGETOWN...MYRTLE BEACH AND CONWAY IN THE PAST HOUR. :(
AN INVERTED TROUGH JUST OFFSHORE IS THE SURFACE FEATURE WE ARE
WATCHING THIS EVENING. IT EXTENDS NORTH FROM A WEAK LOW JUST EAST OF
JACKSONVILLE FL. IN THE UPPER LEVELS A SHORTWAVE TROUGH ACROSS THE
SOUTHERN AND CENTRAL APPALACHIANS WILL SWEEP OFFSHORE AFTER
MIDNIGHT. A PUSH OF WESTERLY MID-LEVEL WINDS BEHIND THIS FEATURE
SHOULD HELP NUDGE THE SURFACE TROUGH FARTHER OFFSHORE AS WELL. OUR
LOW LEVEL WINDS WILL BECOME QUITE LIGHT AS THE TROUGH SHIFTS
OFFSHORE LATE...WITH LITTLE OPPORTUNITY FOR THE CHILLIER AIR IN THE
MOUNTAINS TO ADVECT DOWN TOWARD THE COAST.
OVERNIGHT LOW TEMPERATURES ARE STILL EXPECTED TO RANGE FROM THE MID
50S ON THE COAST TO AROUND 50 ON THE INTERSTATE 95 CORRIDOR. THIS IS
ON THE HIGH END OF MOS GUIDANCE BUT SEEMS REASONABLE GIVEN
PREDOMINANTLY CLOUDY SKIES AND NO SUBSTANTIAL COLD ADVECTION EXPECTED
THROUGH DAYBREAK.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BE PRESENT OFFSHORE ON
SAT. THIS TROUGH WILL LIFT N AND THEN DISSIPATE THROUGH SAT NIGHT.
EXPECT ANY LIGHT PRECIPITATION TO BE ENDING DURING SAT. INLAND
AREAS SHOULD SEE AN END TO THE SHOWERS IN THE MORNING. SHOWERS MAY
LINGER ALONG THE COAST INTO THE AFTERNOON...ESPECIALLY ACROSS THE
CAPE FEAR COAST IN CLOSEST PROXIMITY TO THE TROUGH. MOISTURE
PROFILES AND MODEL SOUNDINGS SHOW A GRADUAL DECREASE IN MOISTURE
ON SAT. A PRONOUNCED NEAR SURFACE INVERSION LINGERS INTO SAT
MORNING...BUT EVENTUALLY THE LOW-LEVEL MOISTURE DOES SCOUR OUT.
THIS SHOULD ALLOW PARTIAL SUNSHINE TO DEVELOP SAT AFTERNOON WITH
THE GREATEST CLOUD COVER LIKELY PERSISTING ACROSS THE CAPE FEAR
REGION. A DEEPENING AND STRENGTHENING S TO SW FLOW WILL ENVELOP
THE AREA SUN AND SUN NIGHT. ANOTHER PRONOUNCED LOW-LEVEL INVERSION
IS EXPECTED TO DEVELOP SAT NIGHT AND THIS WILL LINGER INTO SUN
MORNING. THIS INVERSION SHOULD ALLOW LOW STRATUS TO DEVELOP AND
PERSIST INTO A GOOD PORTION OF SUN MORNING. AT THE SAME TIME...MID
AND HIGH LEVEL MOISTURE WILL BE INCREASING AS PRECIPITABLE WATER
VALUES CLIMB TO ABOUT AN INCH AND THREE- QUARTERS SUN EVE AND
NIGHT. THUS...SUN LOOKS TO BE A RATHER CLOUDY DAY THROUGHOUT. THE
COLUMN BECOMES SUFFICIENTLY MOIST IF NOT SATURATED THROUGH A DEEP
LAYER SUN NIGHT AND WILL SHOW POPS INCREASING TO LIKELY OVERNIGHT.
IT IS POSSIBLE SHOWERS DEVELOP EARLIER ON SUN...BUT MOST OF THE
RAINFALL IS EXPECTED SUN NIGHT AND POSSIBLY INTO MON. AT THIS TIME
WILL KEEP MENTION OF ONLY SHOWERS. HOWEVER...INCREASING CAPE
VALUES WERE NOTED AND SO THERE IS A SMALL CHANCE FOR A RUMBLE OF
THUNDER ALTHOUGH AT THIS TIME...FEEL THE RISK WILL BE CONFINED TO
OFFSHORE AREAS WHERE BAROCLINICITY WILL BE HIGHEST.
TEMPS WILL BE A DEG OR TWO ABOVE NORMAL BY DAY AS DEVELOPING WARM
AIR ADVECTION IS MODERATED BY CONSIDERABLE CLOUD COVER...ESPECIALLY
ON SUN. THIS WILL PUT HIGH TEMPS MAINLY IN THE LOWER TO PERHAPS MID
70S. LOW TEMPS WILL HOWEVER BE WELL ABOVE NORMAL...IN THE 50S SAT
NIGHT AND IN THE 60S SUN NIGHT. THE NORMAL LOW TEMPS FOR MID NOV ARE
IN THE MID 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...THE MID LEVEL PATTERN WILL CONSIST OF MAINLY A
FLAT/ZONAL FLOW BEYOND MONDAY WHEN A WEAKENING TROUGH WILL USHER
THROUGH ANOTHER FAST MOVING FRONT. I DID MAINTAIN THE LIKELY POPS
WITH THIS FEATURE FOR ALL OF MONDAY...AT LEAST THROUGH 0000 UTC
TUESDAY AS THERE REMAINS JUST ENOUGH DISAGREEMENT IN TIMING BETWEEN
THE FASTER GFS SOLUTIONS AND SLOWER WPC PREFERRED ECMWF ENSEMBLE
MEAN. WEEKEND SHIFTS SHOULD BE ABLE TO FINE TUNE TIMING.
BEYOND THIS...HIGH PRESSURE BUILDS IN BUT THE COLD AIR ADVECTION IS
DELAYED SOMEWHAT AS 850MB TEMPERATURES DON/T BOTTOM OUT UNTIL
WEDNESDAY AFTERNOON. OVERALL TEMPERATURE TRENDS ARE SOMEWHAT BELOW
NORMAL WITH WEDNESDAY AND THURSDAY THE COOLEST WARMING A BIT FRIDAY
BASICALLY DUE TO AIR MASS MODIFICATION AND THE DEVELOPMENT OF A
COASTAL TROUGH. TUESDAY TEMPERATURES ARE RIGHT AROUND NORMAL.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...EXPECT VFR CONDITIONS THIS EVENING TO DETERIORATE TO
MVFR/IFR OVERNIGHT ALONG WITH INCREASING PCPN CHANCES. CURRENT RADAR
IMAGERY SHOWS SHRA OFFSHORE ASSOCIATED WITH A COASTAL TROUGH. HAVE
INCLUDED VCSH FOR THE COASTAL TERMS TONIGHT WITH TEMPO PERIODS OF
-SHRA POSSIBLE BEFORE MIDNIGHT. BETTER PCPN CHANCES WILL DEVELOP
AFTER MIDNIGHT AS MOIST ISENTROPIC LIFT BRINGS RAIN TO OUR AREA...
MORE CONCENTRATED ALONG THE COAST. CIGS ARE EXPECTED TO LOWER TO
MVFR AFTER 06Z AS PCPN HELPS SATURATE THE LOWER LEVELS. IFR IS
CERTAINLY POSSIBLE...PERHAPS MORE LIKELY AT KFLO/KLBT WHERE A MORE
PRONOUNCED INVERSION SETS UP. THERE IS MORE UNCERTAINTY FOR THE
COASTAL SITES...SO WILL KEEP PREVAILING MVFR ATTM. THE RAIN WILL
COME TO AN END SATURDAY MORNING...THOUGH MVFR CIGS COULD LINGER INTO
THE LATE MORNING BEFORE IMPROVING TO VFR. THE WINDS WILL BE LIGHT
AND VARIABLE FOR MUCH OF THE PERIOD...BECOMING EAST AROUND 5 KTS
DURING THE DAY.
EXTENDED OUTLOOK...MVFR/IFR FOG POSSIBLE ON SUNDAY MORNING. EXPECT
SHOWERS AND PERIODS OF MVFR/IFR EARLY MONDAY WITH A COLD FRONT.
STRATUS POSSIBLE ALONG THE COAST ON WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM FRIDAY...AN INVERTED SURFACE TROUGH EXTENDS SOUTH-TO-
NORTH ACROSS THE CAROLINA COASTAL WATERS. ITS EXACT LOCATION IS
TOUGH TO PIN DOWN WITH SPARSE OBSERVATIONS...BUT BASED ON WIND
DIRECTIONS AT THE BEACHES AND AT THE FRYING PAN SHOALS BUOY
PROBABLY LIES 10-15 MILES EAST OF CAPE FEAR AND 40-45 MILES EAST OF
MYRTLE BEACH AND GEORGETOWN. THIS TROUGH SHOULD WEAKEN AND SHIFT
EAST AND FARTHER OFFSHORE OVERNIGHT AS AN UPPER LEVEL TROUGH PASSES
OVERHEAD AFTER MIDNIGHT.
WINDS EAST OF THE TROUGH AXIS ARE GENERALLY E-NE IN THE 8-12 KNOT
RANGE...WHILE EAST OF THE TROUGH OVER THE OFFSHORE WATERS THEY ARE
SOUTHEAST NEAR 15 KNOTS AT THE FRYING PAN SHOALS BUOY WITH
GUSTS TO 17 KNOTS. SEAS HAVE BUILT TO 4 FT OFFSHORE AND TO 2.5 FEET
AT THE BUOY JUST SOUTH OF CAPE FEAR.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BISECT THE WATERS ON
SAT. THIS TROUGH WILL LIFT N OF THE AREA SAT NIGHT AND DISSIPATE.
A COLD FRONT WILL APPROACH FROM THE W SUN AND SUN NIGHT. THE
APPROACH OF THIS FRONT WILL GRADUALLY TIGHTEN WHAT WILL OTHERWISE
BE A SLACK GRADIENT THIS WEEKEND. THE STRONGEST WINDS ARE EXPECTED
SUN NIGHT. THE WINDS WILL BE LIGHT ENE TO E SAT. THE DIRECTION
WILL VEER TO SE SAT NIGHT AND TO S ON SUN. WINDS WILL EVENTUALLY
COME AROUND TO SW MON MORNING. WIND SPEEDS WILL REACH UP TO 15 TO
20 KT SUN NIGHT. SEAS WILL BE 2 TO 3 FT SAT THROUGH SUN AND THEN
BUILD TO 4 TO POSSIBLY 5 FT SUN NIGHT. AN 8 TO 10 SECOND SE SWELL
WILL BECOME MORE SIGNIFICANT LATE SUN AND SUN NIGHT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...THE MAIN FEATURE FOR THE MARINE COMMUNITY WILL
BE THE FRONT THAT MOVES ACROSS THE WATERS EARLY IN THE PERIOD. THE
TIMING REMAINS CONFIDENCE CHALLENGED BUT FOR NOW IT LOOKS LIKE A
LATE AFTERNOON WIND SHIFT FROM THE SOUTHWEST TO WEST. NOT THE MOST
DYNAMIC OF SYSTEMS SO WINDS WILL TAKE SOME TIME...BY TUESDAY MORNING
TO REACH MARGINAL SMALL CRAFT CRITERIA WITH A 20-25 KNOT RANGE.
WINDS HAVE A GOOD CHANCE TO STAY ELEVATED AS COLD AIR ADVECTION LAGS
WELL BEHIND THE FRONT AND WILL PROBABLY HOVER AROUND 20 KNOTS
THROUGH THE END OF THE PERIOD. SEAS WILL BUILD WITH THE WINDS FROM
INITIAL VALUES OF 2-4 FEET TO 4-7 FEET BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
937 PM EST FRI NOV 15 2013
.SYNOPSIS...
MOISTURE INCREASES FROM SOUTHWEST...AS DISTURBANCE ALOFT PASSES
TONIGHT. WARMING TREND THROUGH THE WEEKEND. STRONG COLD FRONT
CROSSES SUNDAY NIGHT. IN FAST FLOW ALOFT...GUSTY SHOWERS LIKELY.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
ENDED THE POPS QUICKER IN THE OVERNIGHT PERIOD PER LOCAL WRF
MODELS AND THE HRRR MODEL. RAIN WEST OF THE TUG FORK RIVER IS MORE
SCATTERED IN NATURE...AND WILL SEE THIS TREND MOVING INTO THE WEST
VIRGINIA COAL FIELDS IN THE NEXT COUPLE OF HOURS.
PREVIOUS DISCUSSION...
RADAR AND SATELLITE IMAGES INDICATE SHOWERS STRUGGLING TO REACH
THE GROUND ACROSS EASTERN KY THIS AFTERNOON. VERY DRY AIR MASS
REMAINS IN PLACE PRODUCING VIRGA FOR THE MOST PART. BELIEVE...THE
COLUMN WILL CONTINUE TO MOISTEN...MAKING FEW OF THESE LIGHT
SHOWERS TO AFFECT THE EASTERN MOUNTAINS LATER THIS EVENING AND
TONIGHT.
BREEZY FLOW WILL SUBSIDE LATER TONIGHT AND BECOME MORE SOUTHERLY
OVERNIGHT. ADDITIONAL LIGHT SHOWERS WILL BE POSSIBLE ACROSS THE
SOUTHERN COAL FIELDS OF WV EARLY SATURDAY.
KEPT POPS REACHING LIKELY THIS EVENING ACROSS THE SOUTHEAST HALF
OF OUR CWA. MINOR CHANGES TO TEMPERATURES NEEDED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT ON THE STRONG COLD FRONT THAT RAPIDLY
MOVES ACROSS SUNDAY EVENING AND SUNDAY NIGHT. GIVEN THE ASSOCIATED
NEGATIVELY TILTED UPPER TROUGH SWINGING UP THROUGH THE GREAT LAKES
WITH A DEEPENING SURFACE LOW...THE MODEL TRENDS OF SPEEDING THE
FRONT UP EVEN MORE SEEMS REASONABLE. THE CMC IS EVEN FASTER THAN THE
OTHER SWEET OF MODELS...WHICH ONE CANNOT RULE OUT...BUT WILL STICK
WITH THE VAST MAJORITY OF GUIDANCE WITH THE TIMING. THIS BRINGS THE
FRONT TO THE OHIO RIVER SUNDAY EVENING AND EXITING THE MOUNTAINS
AFTER MIDNIGHT SUNDAY NIGHT...WELL BEFORE DAWN MONDAY.
IN THIS SYNOPTIC SCENARIO...THE LOW LEVEL WINDS WILL BE QUITE STRONG
AND GUSTY MAINLY ALONG AND JUST AHEAD OF THE FRONT...WITH MODEL
FORECASTS OF 60 TO 65 KNOTS OF SOUTHWEST WINDS AT 850MB PRECEDING
THE FRONT. BEING CLOSER TO THE SURFACE LOW...THESE STRONGEST WINDS
WITH THIS SYSTEM WILL BE ACROSS THE NORTHWEST THIRD OF THE AREA
SUNDAY AFTERNOON AND SUNDAY EVENING. THERE WILL ALSO BE A BAND OF
SHOWERS AND A FEW THUNDERSTORMS AS THE FRONT PASSES THROUGH. GIVEN
ALL OF THIS...THE BEST CHANCE OF STRONG AND GUSTY WINDS...POSSIBLY
DAMAGING WINDS...WILL BE IN THE CONVECTION ALONG AND JUST AHEAD OF
THE FRONT AND ESPECIALLY OVER NORTHWEST PORTIONS OF THE AREA. SPC
ALSO HAS A SLIGHT RISK OF SEVERE STORMS SNEAKING IN FROM THE WEST
SUNDAY EVENING WITH THE FRONT...WITH THE MAIN THREAT BEING DAMAGING
WINDS. THIS IS HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK PRODUCT.
AFTER A DRY AND MILD SATURDAY NIGHT...SUNDAY ITSELF WILL FEATURE A
LOT OF CLOUDS AND SCATTERED SHOWERS IN THE WARM ADVECTION AND MOIST
SOUTHERLY INFLOW WELL AHEAD OF THE FRONT ITSELF. WHILE CLOUDS WILL
HELP LIMIT MIXING WITH THE INCREASING LOW LEVEL WINDS...ONE CANNOT
RULE OUT AN ISOLATED DAMAGING GUST IN A SHOWER SUNDAY AFTERNOON...
ESPECIALLY NORTHWEST PORTIONS OF THE AREA FOR THE REASONS MENTIONED
ABOVE. LOOK FOR TEMPS SUNDAY TO BE WELL ABOVE NORMAL...AROUND 70...
DESPITE THE CLOUDS.
FRONT BLASTS THRU SUNDAY NIGHT WITH WESTERLY WINDS BRINGING IN A NICE
DRY SLOT BY MONDAY MORNING. LOOK FOR A DRY AND A MODESTLY COOLER DAY
MONDAY AS MOST OF THE COLD ADVECTION REMAINS NORTH OF US. LATER IN
THE DAY MONDAY...AS WINDS DO TURN MORE NORTHWESTERLY...LOOK FOR
INCREASED COLD ADVECTION AND UPSLOPE TO BRING A LOW CHANCE OF RAIN
SHOWERS IN THE NORTHERN WEST VIRGINIA MOUNTAINS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
GENERALLY QUIET IN THE EXTENDED. SOME SNOW SHOWERS POSSIBLE ACROSS
THE NORTHERN ZONES MONDAY NIGHT AS THE UPPER FLOW TURNS
NORTHWESTERLY BRIEFLY. MAINLY ZONAL FLOW MID WEEK WITH SOME UPPER
RIDGING TAKING HOLD BY WEEKS END. A CHILLY AIRMASS WILL MODIFY TO
NEAR NORMAL BY WEEKS END.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
LIGHT RAIN SHOWERS CURRENTLY OVER THE SOUTHERN COAL FIELDS
WILL SPREAD ACROSS THE SOUTHERN AND CENTRAL MOUNTAINS OVERNIGHT.
SE OHIO MAY SEE SOME SCATTERED LIGHT SHOWERS BUT WILL REMAIN MOSTLY DRY
WITH ABUNDANT CLOUDINESS.
VFR CONDITIONS WITH CEILINGS AT 4 TO 6 THSD FEET AND VISIBILITIES
DROPPING TO 4 TO 5 MILES IN LIGHT RAIN. WITH SHOWERS BECOMING MORE
WIDESPREAD CEILINGS WILL LOWER TO 2000 FEET OVER SOUTHERN MOUNTAIN
INCLUDING BKW VICINITY BY 03Z TO 06Z SATURDAY AND COULD LOWER 1 TO
2 THSD FT BKN/OVC 06Z TO 12Z SATURDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: INTENSITY OF RAIN SHOWERS COULD DETERIORATE
CEILINGS AND VISIBILITIES TO IFR OR WORST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 11/16/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
CRW CONSISTENCY M M M M M H M M H H H H
HTS CONSISTENCY M M M H H H H H H H H H
BKW CONSISTENCY M H H M M M M M M M M H
EKN CONSISTENCY H H H M M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z SUNDAY...
IFR IN STRATUS POSSIBLE ON THE EASTERN SLOPES OF THE WV MOUNTAINS
12Z TO 15Z SUNDAY MORNING...INCLUDING THE GREENBRIER VALLEY.
IN FAST FLOW AREA WIDE...IFR ALSO POSSIBLE IN GUSTY RAIN SHOWERS
SUNDAY AFTERNOON AND SUNDAY NIGHT...AHEAD OF...AND ALONG COLD FRONT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/JMV/30
NEAR TERM...ARJ/26
SHORT TERM...JMV
LONG TERM...30
AVIATION...26/JM
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
518 PM CST FRI NOV 15 2013
.AVIATION...
FOR THE 00Z TAFS...THE PRIMARY CONCERNS ARE THE POTENTIAL FOR SHRA
TONIGHT...AND WINDS TOMORROW. SHRA WILL BE POSSIBLE AFTER
03Z...THOUGH MORE LIKELY AFTER 06Z...ACROSS THE W AND S TX PANHANDLE.
COVERAGE WILL BE LIMITED...SO THERE IS NOT ENOUGH CONFIDENCE TO
INCLUDE ANYTHING MORE THAN VCSH AT THIS TIME. HOWEVER...IF A SHRA
DOES DIRECTLY IMPACT A TERMINAL...GIVEN VERY DRY LOW LEVELS...THERE
IS A THREAT FOR DRY DOWNBURSTS LEADING TO GUSTY AND VARIABLE WINDS.
TOMORROW...WINDS WILL INCREASE SHORTLY AFTER 15Z...APPROACHING
30G40KT. HOWEVER...THERE IS ONE CONCERN THAT CLOUDS WILL NOT CLEAR
OUT IN TIME TO ALLOW MAXIMUM MIXING. EVEN GRANTING THE CLOUDS ARE
SLOWER TO CLEAR OUT...AGREE WITH THE PREVIOUS SHIFT THAT A FEW GUSTS
NEAR 40KT ARE LIKELY AT KAMA AND KDHT. FOR NOW HOWEVER...WILL NOT
ISSUE AN AWW FOR THE WINDS TOMORROW IN CASE AN AWW WILL BE NEEDED
THIS EVENING DUE TO THE GUSTY WINDS WITH SHRA.
VFR CONDITIONS ARE EXPECTED WITH THE EXCEPTION OF A SMALL THREAT OF
DECREASED VISIBILITIES DUE TO BLOWING DUST IN THE STRONGEST WINDS.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 232 PM CST FRI NOV 15 2013/
DISCUSSION...
FORECAST CHALLENGES OVER THE NEXT 24 HOURS INCLUDE CHANCES FOR ANY
CONVECTION TONIGHT AND WIND ADVISORY PROSPECTS FOR SATURDAY. AGREE
WITH WFO LUBBOCK AS THE HRRR AND EVEN THE RUC SHOWING PRECIP MOVING
NORTH AND EAST OUT OF NEW MEXICO THIS EVENING THROUGH TONIGHT ACROSS
MAINLY PARTS OF THE TEXAS PANHANDLE. THIS CONVECTION ASSOCIATED WITH
A SHORTWAVE LOCATED OVER WESTERN AND SOUTHERN NEW MEXICO AND FORECAST
TO LIFT NORTH AND EAST INTO THE SOUTHWEST AND CENTRAL TEXAS PANHANDLE
AFTER 00Z AND 03Z SATURDAY. CONFIDENCE NOT HIGH ENOUGH TO MENTION
THUNDER...BUT WILL INTRODUCE ISOLATED SHOWERS FOR THE TONIGHT
PERIOD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS TONIGHT INTO
SATURDAY MAY PUT A DAMPER ON MIXING THE STRONGER WINDS ALOFT AFTER
15Z TO 17Z SATURDAY...HOWEVER AGREE THAT WIND ADVISORY CRITERIA MAY
BE MET ON THE CAPROCK BY 18Z SATURDAY. CONFIDENCE JUST NOT HIGH
ENOUGH ON TIMING AND LOCATION TO ISSUE A WIND ADVISORY AT THIS TIME.
FEEL THAT A NARROW WINDOW OF WIND ADVISORY CRITERIA POSSIBLE BETWEEN
ABOUT 17Z AND 21Z SATURDAY...WITH WIND SPEEDS GRADUALLY DECREASING
THROUGH THE REMAINDER OF THE AFTERNOON.
COLD FRONT EXPECTED TO PUSH SOUTH AND WEST THROUGH THE PANHANDLES
DURING THE DAY SUNDAY BRINGING COOLER CONDITIONS EARLY NEXT WEEK.
MODERATING TEMPERATURES BY THE MIDDLE OF NEXT WEEK BEFORE ANOTHER
COLD FRONT MOVES THROUGH THE FORECAST AREA LATE NEXT WEEK. MEDIUM
RANGE MODELS INDICATING POSSIBLE PRECIP CHANCES BY THURSDAY NIGHT OR
FRIDAY MAINLY ACROSS THE EASTERN SECTIONS OF THE PANHANDLES AS AN
UPPER TROUGH APPROACHES FROM THE FOUR CORNERS AND SOUTHERN ROCKIES.
WILL HOLD OFF INTRODUCING ANY POPS IN THE THURSDAY TO FRIDAY TIME
FRAME...BUT WILL BUMP UP POPS TO AROUND 10 PERCENT OR SO.
SCHNEIDER
FIRE WEATHER...
MARGINAL ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST UNTIL AROUND
SUNSET THIS EVENING WITH THE 20 FOOT WIND SPEEDS GRADUALLY SUBSIDING
BUT STILL REMAINING IN THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS.
20 FOOT DOWNSLOPING SOUTHWESTERLY WINDS WILL INCREASE AFTER MID TO
LATE MORNING TO AROUND 20 TO 30 MPH WITH HIGHER GUSTS AND MINIMUM
AFTERNOON HUMIDITIES FALLING TO NEAR 20 PERCENT. ALTHOUGH ONLY
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY...THE STRONG
WINDS ALONE MAY JUSTIFY ISSUING A FIRE DANGER STATEMENT FOR ELEVATED
FIRE WEATHER CONDITIONS. ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS
ARE NOT EXPECTED SUNDAY THROUGH LATE NEXT WEEK AS EITHER THE MINIMUM
AFTERNOON RELATIVE HUMIDITIES REMAIN AT OR ABOVE 20 PERCENT OR THE 20
FOOT WIND SPEEDS REMAIN BELOW 15 TO 20 MPH.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
16/02
AREA FORECAST DISCUSSION
NWS SPOKANE WA
653 PM PST Fri Nov 15 2013
.SYNOPSIS...
A strong weather system will spread rain and snow into most of the
region tonight and Saturday with accumulating snow in the
mountains as well as some northern valley locations. The weather
will trend slightly drier on Sunday into early Monday...except
near the Canadian border. A much wetter but warmer weather system
will move into the area late Monday and continue through Tuesday
and Wednesday.
&&
.DISCUSSION...
Looking at recent HRRR runs and some other later model guidance
felt it appropriate to delay the start of the wind advisory a few
hours to 10 PM PST rather than its earlier 7 PM start as the jet
is just a bit slow entering the area. /Pelatti
&&
.AVIATION...
00Z TAFs: This remains a difficult and low confidence forecast due
to a moist winter storm continuing to sweep in from the
northwest...at least for the eastern forecast sites. For MWH and
EAT...confidence is quite good that both sites will remain at VFR
conditions due to downslope flow off the Cascades. The remaining
sites will see a much less confident forecast as precipitation type
will remain problematic until event ends around 10z. We are
confident that the cigs will remain mvfr at best and ifr at worst
for GEG SFF COE PUW with nearly continuous precipitation. What the
precip falls as will be the difficult question to answer. Evening
temperatures and moisture sounding showed freezing level right
around 3000 ft...which suggests the higher sites...GEG PUW and
COE...could remain a rain snow mix or all snow through the entire
time period. The more snow there is the worse the visibilities will
be with values commonly at 1.5 miles or less. The precipitation will
depart the forecast sites just before sunrise...but given the moist
atmosphere and southwest low-level flow we suspect low ceilings will
remain in place through at least 18z. Conditions should improve in
the afternoon...but whether they improve to vfr levels is not a
foregone conclusion. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 33 36 27 40 31 42 / 100 60 10 40 40 10
Coeur d`Alene 33 36 25 38 29 41 / 100 90 20 50 50 20
Pullman 33 37 30 40 32 43 / 100 90 10 40 40 30
Lewiston 38 40 34 46 34 47 / 90 80 20 30 30 20
Colville 34 38 21 37 27 41 / 100 60 20 50 60 20
Sandpoint 33 36 24 37 30 40 / 100 100 40 70 70 50
Kellogg 31 33 26 35 27 39 / 100 100 70 50 60 40
Moses Lake 37 45 29 47 32 47 / 40 10 0 10 10 10
Wenatchee 35 43 30 43 33 46 / 10 10 0 10 10 10
Omak 30 40 26 39 30 43 / 20 10 0 30 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Saturday for Coeur
d`Alene Area.
Winter Storm Warning until 4 AM PST Sunday for Central Panhandle
Mountains-Northern Panhandle.
Winter Weather Advisory until 4 PM PST Saturday for Lewis and
Southern Nez Perce Counties.
WA...Winter Weather Advisory until 4 PM PST Saturday for Northeast
Mountains-Okanogan Highlands.
Wind Advisory from 10 PM this evening to 7 AM PST Saturday for
Lower Garfield and Asotin Counties-Upper Columbia Basin-
Washington Palouse.
Winter Weather Advisory until 4 PM PST Saturday for Northeast
Blue Mountains.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1000 AM PST Thu Nov 14 2013
.SYNOPSIS...
Areas of dense fog will continue over the Lewiston area into this
afternoon. A weak weather system today may produce a few showers
mainly over the mountains. A major weather change is expected to
arrive Friday as a strong weather system from the northwest brings
rain and snow to most of the region. Heavy snow accumulations are
possible in the mountains...as well as the northern valleys and
Idaho Panhandle. Colder air will seep in from Canada on Saturday
behind a cold front with much cooler temperatures through early
next week.
&&
.DISCUSSION...
Update...A weak weather system will track across the area today
bringing mainly mid level clouds above areas of low level stratus
that lingers cross the area due to a moist boundary layer. Models
show a pocket of mid level instability over Northwest Washington
this morning tracking into south Central Washington this
afternoon. In addition the best lift will also track in this area
giving the Cascade crest the best chance of showers with a few
showers also possible along the East Slopes. With only weak
upslope into the Idaho Panhandle, and best dynamic tracking well
west of this area...GFS, NAM, and HRRR show very little shower
activity and shower coverage has been lowered for Sandpoint,
Kellogg, and Lookout Pass.
Overall fog coverage is diminishing this morning but remains dense
in the Lewiston area. This weak system passing through today may
allow for some improvement...but this will likely be a slow
process given fog and stratus is trapped in the valley. Thus areas
of fog has been extended into the afternoon and have adjusted highs
down into the mid 40s.
&&
.AVIATION...
18Z TAFs: A moist boundary layer will linger though 18z Friday
resulting in continued areas of stratus. Most of the stratus has
lifted into 3000-4000 ft AGL except KLWS where VLIFR persists.
Model guidance is not handling this well so confidence is low. The
fog should begin to lift after 22z with a weak system passing
through and then mid level clouds should prevent fog from
reforming tonight. Again however this is a low confidence
forecast. As the next system approaches tonight south-southwest
winds will aid in increasing low level moisture with IFR/MVFR
stratus likely increasing around KGEG/KSFF/KCOE/KPUW by 12z. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 33 37 32 33 24 / 10 10 100 100 90 30
Coeur d`Alene 46 34 37 32 32 23 / 10 20 90 100 100 30
Pullman 46 32 38 33 35 26 / 10 10 90 100 90 30
Lewiston 46 35 44 35 39 30 / 10 10 50 90 80 30
Colville 45 33 38 32 34 17 / 10 10 100 100 90 30
Sandpoint 44 33 36 31 32 19 / 20 20 100 100 100 30
Kellogg 41 34 36 31 32 21 / 20 30 90 100 100 70
Moses Lake 49 31 45 34 41 28 / 10 0 20 20 10 10
Wenatchee 50 35 45 31 41 28 / 10 0 10 20 10 10
Omak 47 32 42 29 36 21 / 10 0 20 30 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Watch from Friday morning through late Saturday
night for Central Panhandle Mountains.
Winter Storm Watch from late tonight through Saturday afternoon
for Northern Panhandle.
WA...Winter Storm Watch from Friday morning through late Saturday
night for Northeast Blue Mountains.
Winter Storm Watch from late tonight through Saturday afternoon
for Northeast Mountains-Okanogan Highlands.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST THU NOV 14 2013
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
322 PM CST THU NOV 14 2013
CONCERNS THROUGH THE SHORT TERM PERIOD INCLUDE RAIN CHANCES INTO
THIS EVENING AND AREAS OF FOG OVERNIGHT.
WATER VAPOR COUPLED WITH RAP 500MB ANALYSIS SHOWING A MID-LEVEL
TROUGH ROTATING EAST OUT OF THE DAKOTAS TOWARD THE UPPER MISSISSIPPI
RIVER VALLEY REGION. RAP SHOWING RIGHT ENTRANCE REGION OF 300MB JET
COUPLED WITH FAIRLY STRONG 700-500MB FRONTOGENESIS ACROSS OUR REGION
AHEAD OF THE APPROACHING MID-LEVEL WAVE. RESULT...PER REGIONAL RADAR
MOSAIC AND SURFACE OBSERVATION WAS A NARROW BAND OF LIGHT RAIN
EXTENDING FROM NORTHEAST WI THROUGH WINONA AND LA CROSSE...TO
PORTIONS OF SOUTHEAST MN/NORTH CENTRAL IA. CLOUDS AND LIGHT
SOUTHERLY SURFACE FLOW KEEPING TEMPERATURES IN CHECK IN THE UPPER
30S TO THE MID 40S.
WILL BE WATCHING THE MID-LEVEL TROUGH TO SLIP EAST ACROSS THE AREA
THIS EVENING/OVERNIGHT WITH BETTER FRONTOGENESIS EXITING EAST EARLY
ON IN THE EVENING. THIS SHOULD BRING AND END TO ANY LIGHT RAIN
ACTIVITY. A WEAK SURFACE TO MID-LEVEL RIDGE OF HIGH PRESSURE BUILDS
IN TOWARD MORNING. AS A RESULT...EXPECTING A GENERAL CLEARING TREND
LATER THIS EVENING THROUGH THE REST OF THE NIGHT. CONCERN THEN
BECOMES FOG POTENTIAL WITH RADIATIONAL COOLING AND RELATIVELY MOIST
LOWER BOUNDARY LAYER GIVEN TODAY/S LIGHT RAINFALL. WENT WITH AREAS
OF FOG IN THE MAIN RIVER STEMS AND PATCH FOG ELSEWHERE. WILL HAVE TO
WATCH THIS CLOSE OVERNIGHT AS ANY FURTHER CLEARING/RADIATIONAL
COOLING COULD LEAD TO POCKETS OF DENSE FOG IN THE MORNING AROUND
COMMUTE TIME.
FOR FRIDAY...MODEL SOUNDING SHOWING THE INVERSION BREAKING AROUND
NOON WITH SOUTHERLY FLOW KICKING IN ON THE BACKSIDE OF THE DEPART
HIGH AND IN ADVANCE OF APPROACHING TROUGH OVER THE HIGH PLAINS.
UNDER PARTLY CLOUDY SKIES...LOOK FOR TEMPERATURES TO MODERATE INTO
SLIGHTLY ABOVE SEASONAL NORMAL TERRITORY AS READING REACH INTO THE
UPPER 40S TO THE LOWER 50S.
SOUTHERLY SURFACE FLOW CONTINUES INTO FRIDAY NIGHT AHEAD OF THE
APPROACHING TROUGH WITH INCREASING 290K ISENTROPIC LIFT/850MB
MOISTURE TRANSPORT. THIS STRONGEST OF THIS FORCING WILL REMAIN JUST
TO OUR WEST THROUGH 12Z SATURDAY MORNING FOR BEST CHANCE OF COLUMN
SATURATION/RAINFALL. WENT WITH A SMALL/20 PERCENT CHANCE OF RAIN
WEST OF A CHARLES CITY TO ROCHESTER LINE AFTER 3 AM SATURDAY.
SOUTHERLY FLOW/INCREASING CLOUDS WILL KEEP TEMPERATURES UP IN THE
MID-UPPER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY) 330 PM CST THU NOV 14 2013
LOOK FOR A RAPID EXPANSION OF RAIN ACROSS THE AREA SATURDAY MORNING
AS BROADSCALE SOUTHERLY FLOW/LIFT/MOISTURE TRANSPORT MOVE SQUARELY
INTO THE REGION. FAIRLY MILD CONDITIONS WITH HIGHS IN THE UPPER 40S
TO MIDDLE 50S CAN BE EXPECTED SATURDAY. MILD/MOIST CONDITIONS ALONG
WITH DYNAMICS/MID-LEVEL STEEPENING LAPSE RATES WILL ALSO PRODUCE A
SMALL CHANCE OF THUNDER BY AFTERNOON.
LOOK FOR THE LIKELIHOOD OF RAIN AND POCKETS OF THUNDER TO CONTINUE
ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY AS STRONGER SURFACE
CYCLOGENESIS TAKES PLACE AND MOVES NORTHEAST ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. STILL SOME UNCERTAINTY BETWEEN THE
MODELS ON INTENSITY AND EXACT TRACK OF THE LOW...BUT ALL POINT
TOWARD OUR AREA BEING IN THE WARM SECTOR OF THE LOW...ESPECIALLY THE
ECMWF. THE NAM PRODUCES 1200-1500J/KG OF 0-3KM ML MUCAPE SUNDAY
ACROSS PORTIONS OF FAR SOUTHWEST WI IN THE WARM SECTOR WITH AMPLE
BULK SHEAR. GIVEN THIS SIGNAL AND SYSTEM DYNAMICS..WILL HAVE TO
WATCH FOR A SEVERE THUNDERSTORM POTENTIAL ACROSS THAT AREA.
OTHERWISE...MODEL CONSENSUS PRODUCES HIGH TEMPERATURES SUNDAY IN THE
UPPER 40S TO THE MIDDLE 50S.
GFS AND ECMWF CONTINUE AT ODDS ON MOVEMENT/INTENSITY OF THE SURFACE
LOW THROUGH SUNDAY NIGHT...WITH THE ECMWF REMAINING SLOWER/MORE
INTENSE AS IT LIFTS INTO UPPER MICHIGAN. THIS WOULD PRODUCE
DEFORMATION RAIN CHANGING TO POSSIBLY MEASURABLE SNOW FOR MUCH OF
THE AREA. THE GFS ON THE OTHERHAND IS MORE OPEN/PROGRESSIVE WITH THE
LOW...LIFTING THE PRECIPITATION OUT OF THE AREA BY MIDNIGHT SUNDAY
NIGHT. WILL GO WITH A MODEL CONSENSUS FOR NOW UNTIL THERE IS BETTER
AGREEMENT...WHICH PRODUCES A 30-40 PERCENT CHANCE OF RAIN
EARLY...CHANGING OVER TO SNOW.
COLD AIR ADVECTION ON BLUSTERY NORTHWEST WINDS EXPECTED ON MONDAY
BEHIND THE DEPARTING LOW. A FEW SNOW SHOWERS WILL ALSO BE POSSIBLE
ACROSS NORTH CENTRAL WI IN THIS COLD CYCLONIC FLOW. LOOK FOR HIGHS
ONLY IN THE 30S.
A FAIRLY STRONG RIDGE OF HIGH PRESSURE MOVES ACROSS THE AREA MONDAY
NIGHT THROUGH WEDNESDAY FOR A QUIET PERIOD. TEMPERATURES WILL REMAIN
CHILLY THOUGHT WITH HIGHS IN THE 30S AND LOWS IN THE TEENS AND LOWER
20S.
NEXT CHANCE OF PRECIPITATION FOR THE AREA LOOKS TO BE ON THURSDAY AS
WARM AIR ADVECTION AND WEAK MOISTURE TRANSPORT TAKE PLACE AHEAD OF A
TROUGH OF LOW PRESSURE MOVING OUT OF THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
1144 AM CST THU NOV 14 2013
BROAD TROUGH PASSING THROUGH NORTHERN STATES HAS CREATED MID LEVEL
FRONTOGENETIC BAND OF LIGHT RAIN FROM NORTHERN WISCONSIN BACK TO
NORTHWEST IOWA. VFR CONDITIONS PREVAIL EVEN WITH THIS. BAND SHOULD
CONTINUE TO PROGRESS EAST THROUGH THE DAY WITH MODEL HINTS OF
WEAKENING IN FORCING AS IT DOES. BESIDES OCCASIONAL LIGHT RAIN FOR
AN HOUR OR TWO...MINIMAL IMPACT. WEAKENING NATURE OF PASSING SYSTEM
LIKELY WILL NOT CREATE MUCH OF A WIND SHIFT EITHER.
WITH TEMPERATURES BEING HELD BACK A BIT TODAY...AND SMALL AMOUNT OF
RAIN FALLING...COULD SEE ENOUGH LOW LEVEL SATURATION AS WINDS BECOME
LIGHTER TONIGHT FOR PATCHY FOG. HIGHEST RISK APPEARS TO BE ALONG
MISSISSIPPI RIVER AND EAST. IF FOG DOES FORM IT SHOULD BE SHALLOW
AND BURN OFF QUICKLY FRIDAY MORNING. THIS WILL HAVE TO BE WATCHED
THIS EVENING BUT FOR NOW KEPT FOG IN VICINITY OF TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...SHEA
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 248 PM CST THU NOV 14 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE
TROUGH/WARM FRONT MOVING EAST ACROSS THE NORTHERN MISSISSIPPI
VALLEY EARLY THIS AFTERNOON. ELEVATED FRONTAL ZONE/RIGHT REAR QUAD
OF JET STREAK IS PRODUCING A BAND OF SPRINKLES OR VERY LIGHT RAIN
FROM NORTHWEST IOWA TO NORTHEAST WISCONSIN. A FEW OBS OVER SW
WISCONSIN ARE SHOWING THE RAIN REACHING THE GROUND...AND THINK THE
SAME CAN BE SAID OVER CENTRAL AND NORTHEAST WISCONSIN. THIS BAND
SHOULD CONTINUE TO MOVE SOUTHEAST OVER THE REST OF THE AFTERNOON
AND REACH THE FOX VALLEY BEFORE 00Z. CLEARING SKIES ARE WORKING
INTO WESTERN WISCONSIN BEHIND THE FRONT WITH TEMPERATURES RISING
INTO THE MIDDLE 50S. THEN ANOTHER AREA OF STRATUS IS WORKING
SOUTHEAST OVER NORTH DAKOTA AND NORTHERN MINNESOTA. FORECAST
CONCERNS INCLUDE CLOUD AND LIGHT PRECIP TRENDS...FOLLOWED BY
TEMPS.
TONIGHT...THE SHORTWAVE TROUGH MOVING INTO THE WESTERN GREAT LAKES
WILL MOVE ACROSS THE LAKE SUPERIOR REGION TONIGHT. IT WILL PUSH A
ELEVATED FRONTAL ZONE ACROSS NORTHEAST WISCONSIN EARLY THIS
EVENING BEFORE EXITING BY MIDNIGHT. HAVE KEPT A CHANCE OF SPRINKLES
GOING INTO THE EVENING TO ACCOUNT FOR UPPER DIVERGENCE AND WEAK
CONVERGENCE ALONG THE FRONTAL ZONE. ONCE MID AND UPPER CLOUDS
DEPART EAST-CENTRAL WISCONSIN LATE IN THE EVENING...MODELS SHOW
MID-LEVEL DRYING TAKING PLACE ACROSS THE REGION. THINK THIS WILL
LEAD TO CLEARING ACROSS ALL BUT FAR N-C WISCONSIN. AREA OF CLOUDS
ACROSS NORTHERN MINNESOTA/NORTH DAKOTA LOOK TO AT LEAST GRAZE
NORTHERN WISCONSIN...SO HAVE KEPT PARTLY TO MOSTLY CLOUDY CONDITIONS
GOING THERE THROUGH THE NIGHT. STATISTICAL GUIDANCE SHOWS LOW
STRATUS OR FOG DEVELOPING WHERE SKIES CLEAR OUT...AND WOULD BE
POSSIBLE IF DEWPOINTS CAN RISE INTO THE LOWER OR MIDDLE 30S..LIKE
THEY DID OVER MINNESOTA. THINK THIS WILL OCCUR ACROSS OUR AREA LATE
THIS AFTERNOON AND EVENING AS THE SURFACE TROUGH MOVES THROUGH...BUT THERE
MAY BE TOO MUCH WIND FOR FOG TO DEVELOP...SO LOW STRATUS IS A BETTER
OPTION. AFTER PARTIALLY CLEARING SKIES THIS EVENING...WILL INCREASE
CLOUDS LATE TONIGHT WITH ANTICIPATION OF STRATUS DEVELOPING. THE
SREF SUPPORTS THIS IDEA. CONTINUED TO GO WITH THE WARMER SIDE OF
TEMPS TONIGHT...WHICH PLACES THEM IN THE UPPER 20S TO MID 30S.
FRIDAY...WEAK ARCTIC FRONT WILL MOVE ACROSS WESTERN LAKE SUPERIOR
AND THE UPPER PENINSULA DURING THE MORNING...BUT LOSE DEFINITION
ACROSS NORTHERN WISCONSIN. RESIDUAL MOISTURE ALONG THE FRONT WILL
LIKELY LEAD TO SCT OR BKN CLOUD COVER ACROSS THE NORTH. THESE
CLOUDS SHOULD LIFT OFF TO THE NORTHEAST DURING THE AFTERNOON.
ELSEWHERE...ANY SHALLOW FOG/STRATUS SHOULD DISSIPATE EARLY...WHICH
WILL LEAVE A MOSTLY SUNNY OR PARTLY CLOUDY CONDITIONS FOR MUCH OF
THE DAY. HIGHS RANGING THROUGH THE 40S.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 248 PM CST THU NOV 14 2013
PLENTY OF CONCERNS IN THE LONG TERM PORTION OF THE FORECAST...MAINLY
CENTERED AROUND A SECONDARY LOW PROGGED TO MOVE ACROSS THE REGION
LATE IN THE WEEKEND. THE ECMWF AND GEM ARE SLOWER THAN THE GFS IN
EJECTING A STRONG SHORTWAVE TROUGH/SURFACE LOW ACROSS THE PLAINS AND
GREAT LAKES. LOOKING AT HPC DISCUSSIONS...THEY FAVOR USING THE
ECMWF ENSEMBLE MEAN...WHICH HAS MORE SUPPORT FROM OTHER OPERATIONAL
MODELS THAN THE GFS/GFS ENSEMBLE MEAN. NOT CONVINCED SLOWER IS
BETTER IN THIS INSTANCE SINCE THERE IS AN ABSENCE OF BLOCKING ACROSS
THE CONTINENT AND THERE IS A 150KT RELATIVELY ZONAL JET UPSTREAM OF
THE TROUGH. THIS WOULD ARGUE FOR A MORE PROGRESSIVE PATTERN. SO
WITH CONFLICTING SIGNALS...GUESS ITS BEST TO GO WITH AN ECMWF/GFS
BLEND TO MITIGATE THESE DIFFERENCES.
FRIDAY NIGHT THROUGH SUNDAY...MID AND HIGH CLOUDS WILL BE ON THE
INCREASE FRIDAY NIGHT AS LEAD SHORTWAVE ENERGY EJECTS INTO THE
CENTRAL PLAINS. WITH INCREASING CLOUDS AND A TIGHTENING PRESSURE
GRADIENT...WILL SIDE ON THE WARM SIDE OF GUIDANCE. THE LEAD
SHORTWAVE TROUGH WILL MOVE NORTHEAST AND ACROSS WISCONSIN DURING THE
AFTERNOON. AHEAD OF THE TROUGH...A 50+KT LLJ WILL DEVELOP AND
TRANSPORT MOISTURE ACROSS THE STATE. WITH DECENT -DIVQ IN THE MID
AND UPPER LEVELS...AND STRONG MOISTURE ADVECTION IN THE LOW
LEVELS...RAIN IS A SOLID BET LATE SATURDAY MORNING AND THROUGH THE
AFTERNOON. WILL INCREASE POPS. THE MAIN AREA OF RAIN WILL BE
EXITING TO THE NORTHEAST OVER THE COURSE OF SATURDAY EVENING AS THE
REGION GETS TEMPORARILY DRY SLOTTED. PLENTY OF LOW LEVEL MOISTURE
WILL BE LEFT THOUGH...AND WITH WEAK WARM ADVECTION
CONTINUING...SHOULD SEE PLENTY OF CLOUDY COVER AND MAYBE PATCHY
DRIZZLE/FOG LEFT OVER. PREVIOUS SHIFT ALREADY HAD THIS COVERED PRETTY
WELL. THE SECONDARY LOW WILL THEN ORGANIZE ACROSS THE PLAINS AND
LIFT NE ACROSS THE SOUTHEAST HALF OF WISCONSIN ON SUNDAY. SHOULD
SEE ANOTHER ROUND OF PRECIP ARRIVE WITH THIS LOW...HEAVIEST ACROSS
THE SOUTHEAST HALF OF THE FORECAST AREA. PRECIP TYPE LOOKS TO
REMAIN ALL LIQUID. NO SIGNIFICANT CHANGES TO TEMPS.
REST OF THE FORECAST...THE SURFACE LOW WILL EXIT SUNDAY NIGHT AND A
CHANGE OVER TO SNOW IS ANTICIPATED AS COLDER AIR RUSHES IN BEHIND
THE CYCLONE. CANNOT GET EXCITED ABOUT ACCUMS THOUGH...UNTIL MORE
CONSENSUS DEVELOPS IN THE DETAILS. WINDY CONDITIONS WILL ACCOMPANY
THE COLD ADVECTION SUNDAY NIGHT INTO MONDAY. IF THE SLOWER SOLUTION
WORKS OUT...WIND HEADLINES WILL BE POSSIBLE. CLOUDY AND COLD ON
MONDAY WITH HIGHS RETURNING TO THE 20S AND 30S. THEN A SLOW WARMING
TREND ENSUES MID-WEEK ONWARD.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1151 AM CST THU NOV 14 2013
VFR CONDITIONS OVER THE TAF PERIOD...BUT NOT WITHOUT SOME
CONCERNS. WEAK FRONT WILL GENERATE SCATTERED SPRINKLES OR VERY
LIGHT SHOWERS THIS AFTERNOON AND EARLY THIS EVENING. BEHIND THIS
FRONT...AT LEAST PARTIAL CLEARING IS EXPECTED...WHICH LEADS TO THE
POSSIBILITY OF LOW STRATUS OR FOG DEVELOPING. DEWPOINTS ARE STILL
RATHER LOW ALTHOUGH THEY ARE INCREASING GRADUALLY. NOT SURE IF
THEY WILL INCREASE ENOUGH THOUGH...SO TRENDED VSBYS DOWN A LITTLE
AT THE MORE FOG PRONE AREAS AT AUW AND RHI. MVFR STRATUS OVER
NORTHERN MINNESOTA IS MOVING EAST AND COULD GRAZE NORTH-CENTRAL
WISCONSIN. IF IT HOLDS TOGETHER...THE FOG CONCERN WILL DIMINISH.
&&
.MARINE...
ISSUED AT 248 PM CST THU NOV 14 2013
WEST TO NORTHWEST GALES ARE EXPECTED LATE SUNDAY NIGHT INTO MONDAY
NIGHT AS A STRONG AREA OF LOW PRESSURE MOVES AWAY FROM THE AREA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......MPC
AVIATION.......MPC
MARINE.........MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1046 PM CST WED NOV 13 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 251 PM CST WED NOV 13 2013
LOW PRESSURE OVER NORTHWEST ONTARIO COUPLED WITH STRONG HIGH
PRESSURE CENTERED OVER KENTUCKY HAS LEAD TO STRONG PRESSURE
GRADIENT OVER THE FORECAST AREA LATE THIS AFTERNOON. SO FAR MAX
WINDS GUSTS HAVE BEEN GENERALLY IN THE 35 TO 40 MPH RANGE ALONG
THE LAKESHORE COUNTIES FROM MANITOWOC TO DOOR COUNTY. HRRR AND RAP
SUGGEST THAT GRADIENT WILL LIKELY STRENGTHEN A BIT MORE AS WE
APPROACH THE EARLY EVENING...THEN SLACKEN SOMEWHAT AFTER MIDNIGHT.
THUS EXPECT SOUTHWESTERLY WIND GUSTS OF SIMILAR MAGNITUDE TO
CONTINUE UNTIL ABOUT 03Z THIS EVENING. OVER DOOR COUNTY MAX WIND
GUSTS EXPECTED TO BE SOMEWHAT HIGHER...CLOSER TO 45 MPH INTO EARLY
EVENING. GENERALLY FAIR SKIES OVERNIGHT TONIGHT WITH LOWS WARMER
THAN LAST NIGHT MAINLY IN THE 25 TO 30 DEGREE RANGE.
LATEST SUITE OF MODEL GUIDANCE CONTINUES TO ADVERTISE PASSAGE OF
RELATIVELY WEAK AND PROGRESSIVE SHORTWAVE DISTURBANCE THURSDAY
AFTERNOON WITHIN FLAT ZONAL FLOW. PRIMARY FORCING WITH THIS
SYSTEM MAINLY ASSOCIATED WITH RRQ OF UPPER JET AND SOME MODEST
FRONTEGENETIC FORCING. GUIDANCE HAS BEEN FAIRLY CONSISTENT IN
DEPICTING A RELATIVELY NARROW BAND OF MOISTURE AHEAD OF WEAK
SURFACE FRONT. A FEW OF THE MODELS THAT WERE PREVIOUSLY
DRY...INCLUDING THE REG GEM AND WRFARW...ARE NOW SHOWING A NARROW
BAND OF VERY LIGHT QPF TO MOVE RATHER QUICKLY ACROSS THE AREA
BEWTEEN ABOUT 18Z THURSDAY AND 00Z FRIDAY. ONLY MODIFIED POPS
UPWARD SLIGHTLY BUT REMAINED IN CHANCE CATEGORY. STILL APPEARS
THAT NORTHCENTRAL WISCONSIN WILL HAVE THE GREATEST CHANCE TO SEE
SOME VERY LIGHT AND SCATTERED RAIN SHOWER ACTIVITY. AS SYSTEM IS
VERY PROGRESSIVE WITH WEAK FORCING...DO NOT EXPECT MORE THAN SOME
WIDELY SCATTERED AMOUNTS OF MAYBE A FEW HUNDRETHS OF AN INCH. WILL
SEE A GRADUAL INCREASE IN HIGH TO MID-LEVEL CLOUDS THROUGHOUT THE
MORNING AS THE SYSTEM APPROACHES. EXPECT MAX TEMPS TO BE GENERALLY
SIMILAR TO TODAY WITH READINGS IN THE 40 TO 45 DEGREE RANGE.
BOUNDARY LAYER WINDS WILL BE CONSIDERABLY MORE MODEST ON THURSDAY
COMPARED TO TODAY AS GRADIENT BAGGIER WITH APPROACHING SURFACE
FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 251 PM CST WED NOV 13 2013
UPPER LEVEL FLOW SHIFTS DURING THE PERIOD AS A STRONG NORTH-SOUTH UPPER
JET MAX...IN EXCESS OF 160 KNOTS...ACROSS THE WEST COAST OF CANADA
HELPS TO AMPLIFY A TROUGH IN THE WESTERN CONUS. CONDITIONS SHOULD
BE RELATIVELY QUIET THROUGH THE END OF THE WORK WEEK. RAIN IS
EXPECTED TO MOVE INTO THE AREA DURING THE WEEKEND AS A SURFACE LOW
DEVELOPS IN THE PLAINS...WITH A STRONG FLOW OF WARM AND MOIST AIR AHEAD
OF IT. HIGHS WILL BE MUCH ABOVE NORMAL ON SATURDAY AND SUNDAY.
THE 12Z GEM AND 12Z GFS HAD THE FIRST OF TWO SURFACE LOWS PASSING
THROUGH NORTHWEST WI/NORTHEAST MN SATURDAY NIGHT...WITH A SECOND
LOW PASSING THROUGH SOUTHEAST WISCONSIN SOMETIME ON SUNDAY. BOTH
OF THESE MODELS SHOWED A PRETTY WIDESPREAD AREA OF QPF OVER THE
WEEKEND...WITH THE GFS INDICATING QPF AND MUCH COLDER AIR BEHIND
THE SYSTEM. THE 12Z ECMWF HAD A SINGLE...STRONGER SURFACE LOW THAT
WAS FORECAST TO PASS ACROSS NORTHWEST WI SUNDAY AFTERNOON AND
EVENING. IT ALSO HAD SOME LINGERING PRECIPITATION FORECAST BEHIND
THE DEPARTING SYSTEM. RAIN IS LIKELY FOR THE WEEKEND...AND THERE IS
A CHANCE OF PRECIPITATION SUNDAY NIGHT AND MONDAY...CHANGING FROM
RAIN TO SNOW FROM NORTHWEST TO SOUTHEAST. KEPT A CHANCE FOR SNOW
SHOWERS IN THE NORTH LINGERING INTO MONDAY NIGHT.
MUCH COLDER TEMPERATURES ARE IN STORE FOR NEXT WEEK WITH SURFACE
HIGH PRESSURE OVER THE AREA AND A SHIFT TO NORTHWEST FLOW ALOFT.
HIGHS ARE ONLY EXPECTED TO BE AROUND 30 DEGREES FOR THE MIDDLE
PART OF THE WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1041 PM CST WED NOV 13 2013
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH AT LEAST THURSDAY
MORNING. LLWS SHOULD PERSIST AT RHI UNTIL AROUND 08Z...AUW/CWA
AROUND 11Z...AND ATW/GRB UNTIL 14Z. A GRADUAL INCREASE IN
MID/HIGH LEVEL CLOUDS IS EXPECTED LATE TONIGHT INTO THURSDAY
MORNING AHEAD OF AN APPROACHING WEAK FRONTAL SYSTEM. THIS SYSTEM
DOES NOT HAVE MUCH MOISTURE TO WORK WITH...SO MAINLY SPRINKLES ARE
EXPECTED DURING THE LATE MORNING AND AFTERNOON. SOME MVFR CIGS
MAY DEVELOP BY THURSDAY EVG...AS LOW-LEVEL MOISTURE GRADUALLY
INCREASES NEAR THE WEAK FRONTAL BOUNDARY. WILL JUST INCLUDE A
TEMPO GROUP TO COVER THIS FOR NOW...AS CONFIDENCE IS NOT HIGH
ENOUGH TO CARRY PREVAILING MVFR CONDITIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......MG
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
951 PM MST WED NOV 13 2013
.UPDATE...
ISSUED AT 829 PM MST WED NOV 13 2013
SURFACE OBSERVATIONS FROM ACROSS THE AREA HAVE YET TO INDICATE ANY
PRECIPITATION HITTING THE GROUND...NOT TO SAY SOME LIGHT
PRECIPITATION IS NOT OCCURRING IN THE MOUNTAINS. UNR AND CYS
RADARS ARE SHOWING A NICE DONUT HOLE AROUND THE RADARS INDICATIVE
OF MOISTURE NOT REACHING THE GROUND...BUT RATHER MIDLEVEL CLOUDS
AND VIRGA. AT THIS POINT EXPECTING LITTLE IN THE WAY OF
PRECIPITATION REACHING THE GROUND TONIGHT. CHANCE FOR MEASURABLE
RAIN AND SNOW AT ANY ONE LOCATION IS ON THE LOW SIDE. LATEST 00Z
NAM RUN HAS BACKED OFF ON QPF A GREAT DEAL OVER THE 18Z RUN. GFS
RUN WILL BE IN SOON AND EXPECTING A SIMILAR RESULT. THE HRRR IS
PRODUCING LITTLE IN THE WAY OF PRECIPITATION TONIGHT AS WELL. IR
SATELLITE IS ALSO LESS THAN IMPRESSIVE WITH CLOUD TOP WARMING IF
ANYTHING. BACKED OFF ON POPS TONIGHT BUT WAS NOT QUITE CONFIDENT
ENOUGH TO PULL POPS OUT COMPLETELY AT THIS POINT. EITHER WAY
LITTLE TO NO MEASURABLE PRECIPITATION OUTSIDE OF THE
MOUNTAINS...AND EVEN THE MOUNTAINS MAY STRUGGLE TO PICK UP
MUCH PRECIPITATION TONIGHT.
UPDATE ISSUED AT 551 PM MST WED NOV 13 2013
CURRENTLY WATCHING OBSERVATIONS SITES FROM AROUND THE AREA FOR
ANY SIGNS OF SNOW REACHING THE GROUND. NAM AND GFS HAVE BIG
DIFFERENCES IN THEIR QPF FIELDS THIS EVENING. NAM PRODUCES 3
TENTHS OF AN INCH OF LIQUID OVER NORTHERN CONVERSE COUNTY WHICH
WOULD BE EQUIVALENT TO 3 TO 5 INCHES OF SNOW. THE GFS DOES NOT
PRODUCE MUCH MORE THAN A DUSTING OF SNOW. BASED ON OBSERVATIONS
UPSTREAM THE GFS SEEMS TO HAVE A BETTER HANDLE AT THIS TIME.
EXPECTING A FEW INCHES OF SNOW IN THE NORTHERN LARAMIE RANGE WITH
AN INCH OR SO INTO THE SNOWY RANGE...OTHERWISE SHOULD NOT SEE MUCH
SNOW OUTSIDE OF THE MOUNTAINS WITH THIS QUICK MOVING SYSTEM...BUT
WILL BE KEEP A CLOSE EYE ON RADAR THIS EVENING.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 308 PM MST WED NOV 13 2013
A SHORTWAVE TROUGH WAS LOCATED FROM NORTHEAST MONTANA TO SOUTHEAST
IDAHO EARLY THIS AFTERNOON. CLOUDS HAVE INCREASED OVER THE CWA
IN ADVANCE OF THE FEATURE AND ISOLATED SHOWERS WERE CURRENTLY
LOCATED OVER THE NORTH AND WEST PARTS OF THE CWA. THE ASSOCIATED
SURFACE COLD FRONT EXTENDED FROM SOUTHWEST SOUTH DAKOTA TO SOUTH
CENTRAL WYOMING AT 21Z. THE SHORTWAVE TROUGH WILL MOVE QUICKLY
EAST AND WILL BE EXITING THE CWA AROUND 12Z. MEANWHILE...THE FRONT
WILL MOVE ACROSS THE ENTIRE CWA BY 06Z. SOME SHOWERS WILL OCCUR
OVER THE CWA TONIGHT WITH THE NAM DEPICTING MORE QPF THAN THE GFS.
WILL INCREASE POPS SOME OVER THE CWA TONIGHT WITH THE PRECIPITATION
TYPE SLOWLY MIXING WITH AND CHANGING TO SNOW OVER THE LOWER
ELEVATIONS. ONLY A DUSTING OF NEW SNOW IS EXPECTED OVER THE LOWER
ELEVATIONS...WITH AN INCH OR SO OVER THE MOUNTAINS. WESTERLY SURFACE
WINDS GUSTING TO 35 MPH IN AREAS ALONG AND WEST OF THE LARAMIE RANGE
EARLY THIS AFTERNOON WILL SUBSIDE WITH SUNSET AND THE FRONTAL
PASSAGE.
TEMPERATURES WILL BE COOLER OVER THE CWA ON THURSDAY WITH ONLY THE
SNOWY AND SIERRA MADRE RANGES SEEING SOME SNOW SHOWERS. THE NEXT
SHORTWAVE TROUGH...CURRENTLY ENTERING CENTRAL BRITISH COLUMBIA
WILL MOVE SOUTH AND THE AXIS WILL BE BE NEAR THE WESTERN WYOMING
BORDER BY 00Z SATURDAY. MOST OF THE ENERGY WITH THAT FEATURE WILL
BE ON THE SOUTHERN PORTION AT THAT TIME...OVER UTAH AND WESTERN
COLORADO. THE SOUTHWEST WIND FLOW ALOFT OVER THE CWA AHEAD OF
THE SHORTWAVE TROUGH WILL SPREAD CLOUDS OVER THE CWA FRIDAY ALONG
WITH SOME SHOWERS OVER AND WEST OF THE LARAMIE RANGE. THE SNOWY AND
SIERRA MADRE RANGES SHOULD SEE UP TO AN INCH OF NEW SNOW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM MST WED NOV 13 2013
THE SHORTWAVE TROUGH WILL MOVE ACROSS THE ROCKIES FRIDAY NIGHT AND
SATURDAY MORNING. MOST OF THE ENERGY STILL REMAINS SOUTH OF THE
CWA DURING THAT TIME. HOWEVER...OROGRAPHICS WILL PRODUCE SOME
ACCUMULATING SNOW OVER AND NEAR THE MOUNTAINS FRIDAY NIGHT AND
SATURDAY MORNING. THE 12Z GFS IS SLOWER THAN THE ECMWF WITH THAT
SHORTWAVE TROUGH.
THE NEXT SHORTWAVE TROUGH BY 18Z SATURDAY WILL ALREADY BE OVER THE
PACIFIC NORTHWEST AND DIGGING. THE TIMING OF THAT FEATURE IS STILL
HANDLED DIFFERENTLY BY MODELS. THE ECMWF IS STILL SLOWER THAN THE
GFS...BUT IS TRENDING MORE PROGRESSIVE AND TOWARD THE GFS. THE
TROUGH AXIS ON BOTH MODELS IS EAST OF THE CWA BY 18Z SUNDAY.
COLDER AIR WILL MOVE ACROSS THE CWA BEHIND A SERIES OF COLD FRONTS
SATURDAY NIGHT AND EARLY SUNDAY MORNING. BETTER DYNAMICS AND
MOISTURE WITH THIS SYSTEM SHOULD PRODUCE A BETTER CHANCE OF SNOW
OVER THE CWA SATURDAY NIGHT AND SUNDAY MORNING. THE 300 MB JET
WILL BE IN A FAVORABLE POSITION DURING THAT TIME. FOR NOW HAVE
BUMPED UP POPS...WITH POSSIBLY SEVERAL INCHES OF SNOW ACCUMULATING
OVER THE LOWER ELEVATIONS AND MORE OVER THE MOUNTAINS.
COLD TEMPERATURES WILL PERSIST OVER THE CWA ON MONDAY...WITH MODELS
PAINTING SOME JET AIDED QPF OVER THE NORTHEAST PART OF THE CWA
SUNDAY NIGHT AND MONDAY MORNING. SURFACE HIGH PRESSURE WILL BE
OVER THE CWA MONDAY BEFORE MOVING OVER THE PLAINS. HEIGHTS ALOFT
REBUILD OVER THE ROCKIES THROUGH AT LEAST TUESDAY WITH A SURFACE
TROUGH DEVELOPING OVER THE EAST PART OF THE CWA. WARMER AND DRIER
CONDITIONS CAN BE EXPECTED OVER THE CWA FOR TUESDAY. THE NEXT
SHORTWAVE TROUGH MOVES ACROSS THE CWA TUESDAY NIGHT AND WEDNESDAY
WITH THE ECMWF FASTER THAN THE GFS. A COLD FRONT WILL ALSO MOVE
ACROSS THE CWA...BUT AT THIS TIME MODELS ARE NOT SHOWING ANY QPF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 943 PM MST WED NOV 13 2013
QUICK MOVING UPPER LEVEL DISTURBANCE AND TRAILING SURFACE COLD
FRONT ARE PASSING THROUGH THE FORECAST AREA AT THIS TIME. THERE IS
VERY LITTLE MOISTURE ASSOCIATED WITH THIS SYSTEM SO CHANCES FOR
PRECIPITATION ARE FEW AND FAR BETWEEN. SOME OF THE HIGHEST MOUNTAIN
TOPS MAY BE OBSCURED DO TO MID LEVEL CLOUDS AND SNOW...OTHERWISE
MAINLY LOOKING AT VFR TO MVFR CIGS ACROSS THE FORECAST AREA
TONIGHT. ANY MVFR CIGS THAT MIGHT DEVELOP TONIGHT WILL ERODE
SHORTLY AFTER SUNRISE.
&&
.FIRE WEATHER...
ISSUED AT 308 PM MST WED NOV 13 2013
FIRE WEATHER CONCERNS WILL BE MINIMAL OVER THE CWA THROUGH EARLY
NEXT WEEK. AFTER A MILD...DRY AND BREEZY DAY TODAY...A SERIES
OF COLD FRONTS WILL MOVE ACROSS THE CWA TONIGHT THROUGH SUNDAY.
EACH FRONT WILL BRING COOLER AIR WITH A CHANCE OF PRECIPITATION.
THE PRECIPITATION WILL BE MAINLY IN THE FORM OF SNOW AND WILL BE
MOST LIKELY SATURDAY NIGHT AND SUNDAY MORNING. THE LARGER
ACCUMULATIONS OF SNOW WILL OCCUR OVER THE MOUNTAINS. WARMER AND
DRIER CONDITIONS WILL RETURN TO THE REGION TUESDAY AND WEDNESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...LIEBL
SHORT TERM...WEILAND
LONG TERM...WEILAND
AVIATION...LIEBL
FIRE WEATHER...WEILAND
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1136 PM CST Fri Nov 15 2013
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Saturday)
Issued at 250 PM CST FRI NOV 15 2013
On Friday afternoon, an upper trough was located over southern
California and Nevada while a series of weaker lead short wave
troughs were moving through fairly fast west southwest flow aloft
from the four counters into the western Plains. At the surface, low
pressure was deepening in eastern Colorado with intensifying
pressure gradient and southerly flow from southern Texas through the
Dakotas. A pool of quality low level moisture was in place across
northeast Texas and moving into eastern Oklahoma. As the lee surface
low continues to deepen overnight, expect a strong low level jet to
transport this moisture into eastern Kansas with a west to east
gradient while a strong elevated mixed layer and warm advection
builds above the moist boundary layer. The moist advection will
likely occur after a fairly quick evening cool down owing to mostly
clear skies, and the influx of moisture into cooler air along with
fairly strong ascent overnight and dry air aloft may contribute to
periods of drizzle during the early morning hours. There are also
some indications of moistening around 10 thousand feet which may
lead to weak elevated instability and at least some potential for a
few showers given the magnitude of lift. Winds at the surface will
also increase through the night as the pressure gradient strengthens.
Any light shower activity and drizzle will likely come to an end by
late Saturday morning as boundary layer mixing increases and
elevated capping increases. As mixing increases, the low level jet
will begin to mix gusts to the surface. The LLJ is forecast to have
50+ kt winds at 2500 feet AGL which would easily translate 45+ mph
wind gusts to the surface on a clear day, but the stratus deck may
be sufficient to limit overall mixing a bit, and by the time
clearing is forecast to occur, the LLJ will have weakened a bit. The
main question today is whether the depth of mixing will matter given
the strength of winds even 1500 feet AGL and the very strong late
morning pressure gradient. For now, have not issued a wind advisory,
but could certainly see the need to do so if future model guidance
suggests the 12Z NAM and recent RAP runs that highlight an even
stronger low level wind field. It`s a low confidence wind forecast
at this time that could result in peak gusts somewhere between 40
mph and 55 mph, with the strongest winds focused in east central KS.
By late afternoon, another lead short wave will approach the area.
At least partial afternoon clearing should have occurred with
temperatures in the lower 70s and dewpoints in the upper 50s. While
a strong capping inversion will be in place for much of the day, it
appears that the incoming trough will help cool the cap such that
afternoon CINH may decrease into the 10 to 50 J/KG range for a short
period between roughly 3 PM and 7 PM before rapidly increasing
again. Higher Res model guidance suggests MLCAPE in the 500 to 1000
J/KG range during this period while 0-6 km shear is 40 to 60 kts.
While these conditions would normally suggest some potential for a
few strong storms, the primary limiting factor...even with the
incoming short wave trough...is a general lack of any meaningful
surface convergence with the southwesterly low level wind field. The
lack of low level forcing along with a lopsided shear/CAPE balance
suggests it will be difficult to sustain any updrafts. At this time,
will maintain a slight chance of thunderstorms in the eastern parts
of KS generally east of Marysville to Burlington, and if one should
develop it would warrant an attentive eye.
.LONG TERM...(Saturday Night through Friday)
Issued at 250 PM CST FRI NOV 15 2013
By Saturday evening as the boundary layer begins to cool the
southwesterly low level jet increases which will ultimately
strengthen the capping inversion. The increasing low level jet
during the evening forces drier air into the lower levels. If an
elevated storm is able to form after sunset the dry air intrusion
should hinder any persistence. All of these factors should work
against any sustained storm threat across the area...therefore went
with a dry forecast after 00z Sun. Gusty winds continue for the
southeast half of the cwa and especially southeast of the turnpike
overnight Saturday into Sunday. Low temperatures range from the mid
40s in north central KS to the mid 50s in east central KS.
On Sunday morning the main upper level trough axis passes through
the region as well as the associated cold front. The cold front
should clear the area by 15z Sun with a significant drop in dew
points following the passage. Behind the main trough axis
northwesterly flow increases in response to the deepening pressure
field across the upper Midwest as the system becomes negatively
tilted. Forecast soundings show most locations mixing between 800 to
700 mb especially across central KS where dew points are lower. Red
flag criteria is possible Sunday during the day across the western
portions of the area with winds gusting to around 35 mph in
combination with the low relative humidity. Less certain is the
effect cooler air behind the front has on temperatures and how low
the dew points get Sunday afternoon determining min RH. Therefore
did not issue any headlines and will let later shifts evaluate the
latest guidance. High temperatures on Sunday look to reach the upper
50s to low 60s.
In the wake of that system dry northwest mid level flow sets up for
the central US allowing surface high pressure to build into the
region. Winds should begin to decrease Sunday evening with a
relatively calm day in store for Monday. The mid level flow quickly
transitions to a zonal pattern and return flow develops as the high
pressure retreats then the models really start to disagree by mid
week. The 12z ECMWF/GEM suggesting precip chances by Wed as a
shortwave pushes a front through the region, but this lacks any
consistency at this point therefore kept the forecast dry. Although
the better chances for precip appear to be on Thurs and Fri as a
trough approaches from the west coast. The evolution of that system
and the associated surface features is unknown. Have added the
possibility of snow Thurs night and Friday which is advertised by
the 12z ECMWF but confidence is pretty low. Through the extended
temperatures remain near average with highs in the 50s and lows in
the 30s with a cooling trend late in the period.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1128 PM CST FRI NOV 15 2013
Stratus now developing over eastern OK should spread/develop
northward into the Taf sites in the 08Z-11z time frame with mvfr
cigs (IFR at KFOE) as gusty south winds continue. Cigs should
gradually scatter to vfr aft 14z at KMHK with vfr conditions not
working into the KTOP/KFOE until 18z. Also may be some patchy
drizzle as well. Otherwise expect most precip to remain south and
east of the TAF sites through the fcst...with gusty
south/southwest winds of 20-30 gusts to 35kts decreasing aft 23Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Sanders
AVIATION...63
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1242 AM EST SAT NOV 16 2013
.SYNOPSIS...
A DRY DAY WITH WARMER TEMPERATURES. MORNING CLOUDS WILL GIVE WAY
TO SOME SUN IN THE AFTERNOON. A STRONG COLD FRONT WILL BRING WIND
AND RAIN TO THE AREA SUNDAY INTO EARLY MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
HAVE UPDATED OVERNIGHT POPS FOR SOUTHERN SHOWERS TO BE MORE IN
LINE WITH LATEST GUIDANCE. SHORTWAVE RESPONSIBLE FOR THE SHOWERS
IS QUICKLY MOVING INTO CENTRAL PA AND WILL REACH THE EASTERN PART
OF THE STATE AROUND 07Z. WITH SHORTWAVE GONE...SHOWERS EXIT THE
AREA FOLLOWED BY A BRIEF DECREASE IN CLOUD COVER. MID-LEVEL
MOISTURE TO THE SOUTHEAST...VISIBLE ON THE LATEST SAT PICS...WILL
ADVECT NORTHEASTWARD LATE TONIGHT. THIS WILL MEAN ANOTHER
INCREASE IN CLOUDS FROM SOUTHWEST TO NORTHEAST. WILL ADJUSTS
TEMPS TO LATEST GUIDANCE.
MID-LEVEL FLOW INCREASE THIS MORNING AND BACKS TO THE SOUTHWEST.
THIS WILL CONTINUE TO PULL THE MOISTURE NORTHWARD INTO THE UPPER
OHIO VALLEY...IN ADDITION TO WARMER AIR. STRONG WAA WILL BE IN FULL
FORCE BY THIS AFTERNOON AND MID-LEVEL MOISTURE LEVELS WILL
DECREASE. MODEL SOUNDINGS ARE DEPICTING THIS WELL SHOWING THE
OVERALL ATMOSPHERE DRYING OUT LATE THIS MORNING AND THROUGH THE
AFTERNOON. THE COMBINATION OF DECREASING CLOUD COVER AND WAA WILL
ALLOW FOR TEMPS TO GO 5 TO 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
CLOUDS WILL QUICKLY INCREASE TONIGHT AS ANOTHER SHORTWAVE TROUGH
SWINGS THROUGH. THE FIRST WAVE WILL MOISTEN THINGS UP AND THE
SECOND WAVE...MOVING THROUGH AROUND DAWN...WILL PROVIDE SHOWERS
FOR THE REGION BY SUNDAY MORNING.
SUNDAY MORNINGS WAVE WILL EXIT BY EARLY AFTERNOON...WHICH WILL
ALLOW FOR A BRIEF BREAK IN THE WIDESPREAD RAINFALL. SURFACE WINDS
WILL BECOME GUSTY SUNDAY AFTERNOON AS THE SURFACE PRESSURE
GRADIENT TIGHTENS AND THE MIXING LAYER RISES...REACHING THE
STRONG WINDS ALOFT. ITS NOT OUT OF THE QUESTION THAT WINDS GUSTS
SUNDAY AFTERNOON COULD REACH CLOSE TO 40 MPH.
WIDESPREAD SHOWERS QUICKLY RE-ENTER THE AREA LATE SUNDAY AHEAD OF
THE MAIN COLD FRONT. IN ADDITION TO THE SHOWERS...GUSTY WINDS WILL
CONTINUE.
THE CONCERN SUNDAY EVENING/NIGHT WILL BE THE POSSIBILITY FOR
DAMAGING WINDS WITH THE FRONTAL PASSAGE. COLD FRONT WILL QUICKLY
MOVE THROUGH OHIO SUNDAY EVENING...REACHING WESTERN PA AROUND
MIDNIGHT. GUSTY WINDS WILL BE ONGOING AHEAD OF THE FRONT...BUT IT
APPEARS THAT THERE WILL BE AN INCREASED THREAT FOR DAMAGING WINDS
WITH THE PASSAGE OF THE FRONT. MODELS ARE SHOWING A THIN LINE OF
STRONG LOW LEVEL FORCING AND MOISTURE CONVERGENCE RIGHT AHEAD OF
THE SURFACE BOUNDARY. 0-1KM SHEAR VALUES WILL BE IN EXCESS OF
50KTS SUNDAY EVENING...PLENTY STRONG ENOUGH TO SUSTAIN ELEVATED
CONVECTION. MODEL SOUNDINGS ARE PORTRAYING A DEEP MIXING LAYER
DEVELOPING WITH STRONG LAPSE RATES MEANING THE VERY STRONG WINDS
ALOFT WILL HAVE NO ROADBLOCKS MIXING DOWN TO THE SURFACE.
CONVECTION WOULD NEED TO BE ELEVATED AS CONVECTIVE TEMPS AHEAD OF
THE FRONT ARE NEAR 70 DEGREES. THIS SCENARIO COULD PLAY OUT VERY
SIMILARLY TO THE WIND EVENT THAT OCCURRED A COUPLE OF WEEKS AGO
WHEN A LINE OF SHOWERS DEVELOPED WITH THE FRONT AND PROVIDED A
BRIEF PERIOD OF DAMAGING WINDS.
THE OTHER PART OF THE STORY THAT NEEDS TO BE CONSIDERED IS THE
STRONG PRESSURE RISES BEHIND THE FRONT AND SHOWERS. IT IS
POSSIBLE THAT THIS FEATURE COULD PROVIDE A SECOND ROUND OF STRONG
WIND GUSTS. THE MIXING LAYER WILL SHRINK...BUT WINDS ALOFT ARE
STILL PLENTY STRONG. IF THIS SECOND FEATURE COMES TO FRUITION...IT
TOO WOULD BE BRIEF.
MONDAY IS NOT SETTING UP AS TOO BAD OF A DAY. ATMOSPHERE IS DRY
BEHIND THE FRONT AND THE CAA WILL BE WEAK AND SLOW. TEMPS MONDAY
WILL BE MORE SEASONABLE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A BRIEF PERIOD OF COLDER AIR AND THE POSSIBILITY FOR SNOW SHOWERS
MONDAY NIGHT. HIGH PRESSURE WILL RETURN DRY WEATHER AND PROVIDE
MODERATING TEMPERATURES FOR THE REMAINDER OF THE LONG TERM.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WEAK TROUGH PASSING OVER THE AREA TONIGHT COULD RESULT IN PERIODS
OF LIGHT SHOWERS PRIMARILY SOUTH OF PITTSBURGH...BUT OPTED NOT
TO INCLUDE IN THE 00Z TAF PACKAGE FOR KMGW OR KZZV AS EXPECT
COVERAGE TO BE SCATTERED AND DURATION...IF ANY...BRIEF. VFR CONDS
EXPECTED OVERNIGHT...BUT LATEST RUC SOUNDINGS INDICATE THE
POTENTIAL FOR MVFR CLOUD COVERAGE BY MORNING BETWEEN 11Z AND 12Z.
VFR CONDTIONS THEN EXPECTED AREAWIDE BY LATE MORNING.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RSTRNS ALG WITH A PD OF LLWS AND GUSTY WNDS ARE EXPD WITH THE APCH
AND PASSAGE OF A STG CDFNT SUN AND SUN NGT. RSTRNS WL REMAIN PSBL
THRU ERLY TUE AS AN UPR TROF CROSSES THE GT LKS IN NW FLOW. BLDG
HIGH PRES RTNS VFR CONDS LT TUE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
308 AM CST SAT NOV 16 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 308 AM CST SAT NOV 16 2013
A WARM SLY FLOW COVERED THE FA AT 08Z WITH A WEAK AREA OF LOW
PRESSURE IN NE ND. A WARM FRONT EXTENDED FROM THE LOW CENTER INTO
THE NORTHERN PART OF THE AREA WHILE A COLD FRONT WAS IN THE EASTERN
DAKOTAS. A MIX OF MID AND HIGH CLOUDS WERE DRIFTING OVER THE WESTERN
GREAT LAKES IN THE WAA AHEAD OF THE LOW. MEANWHILE...UPPER LEVEL
RIDGING WAS IN PLACE AS SEEN IN WATER VAPOR IMAGERY. EXPECT THE
UPPER RIDGE TO MOVE E OF THE AREA THIS MORNING WHILE A TROF DEEPENS
OVER THE LEE OF THE ROCKIES. THIS TROF WILL EJECT A VORT MAX INTO
CENTRAL MN REACHING NW WI BY 18Z. BROUGHT IN SOME SMALL POPS BY 16Z
AND CONTINUE TO SPREAD THEM INTO MUCH OF THE FA BY 18Z IN RESPONSE.
LEFT THE WESTERN EDGE DRY ATTM. LATEST MODELS HAVE BACKED OFF ON THE
POSSIBILITY OF THUNDERSTORMS UNTIL ABOUT 21Z IN NW WI AND HAVE
ADJUSTED ACCORDINGLY. A RUMBLE OF THUNDER MAY BE HEARD AROUND THE
PERIPHERY OF WESTERN LAKE SUPERIOR INTO PINE COUNTY MN. BEST
INSTABILITY APPEARS TO BE OVER THE EASTERN WI PORTION OF THE FA AND
HAVE AN ISOLD MENTION THERE. POPS WILL GRADUALLY INCREASE THROUGH
THE AFTERNOON AS A PARADE OF VORT MAXES LIFT NEWD FROM THE BASE OF
THE UPPER TROF THROUGH 00Z SUNDAY. PCPN WILL BE ALL LIQUID DUE TO
THE WARM ATMOSPHERE IN PLACE.
THE UPPER LEVEL LONG WAVE TROF OVER THE ROCKIES CONTINUES TO DEEPEN
TONIGHT. MORE VORT MAXES WILL CONTINUE TO EJECT OUT AND INTO THE
WESTERN GREAT LAKES. INTERMITTENT BOUTS OF LIGHT RAIN WILL AFFECT
THE FA THROUGH THE NIGHT. THE EXCEPTION WILL BE ALONG THE SOUTHERN
EDGE LATE TONIGHT WHEN A DRY WEDGE MOVES NEARBY. HAVE A FOG MENTION
BEGINNING LATE TONIGHT AS WELL.
THE UPPER TROF FINALLY MOVES OUT OF THE ROCKIES INTO THE MIDWEST
SUNDAY AND BECOMES NEGATIVELY TILTED. A SFC LOW BECOMES ORGANIZED
AHEAD OF THE TROF AND DEEPENS AS IT MOVES FROM SOUTHERN WI INTO
LOWER MI BY 00Z MONDAY. BEHIND THIS LOW...CAA BEGINS OVER THE FA
ALLOWING FOR A MIX OF RAIN AND SNOW IN THE IN THE NW CORNER SUNDAY
MORNING BEFORE CHANGING TO ALL SNOW IN THE AFTERNOON. ONLY A MINOR
ACCUMULATION IS EXPECTED. ALL RAIN IS FORECAST FROM WESTERN LAKE
SUPERIOR TO THE BRAINERD LAKES E INTO NW WI AS THE ATMOSPHERE WILL
BE SLOW TO COOL.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 308 AM CST SAT NOV 16 2013
THE NORTHLAND WILL BE IN THE WAKE OF A PASSING STRONG LOW PRESSURE
SYSTEM WHICH WILL BE MOVING FROM EASTERN ONTARIO TO WESTERN QUEBEC.
COLD AND GUSTY NW FLOW WILL DEVELOP ACROSS THE NORTHLAND SUNDAY
NIGHT. THERE MAY BE LINGERING LIGHT RAIN AND SNOW ACROSS THE
NORTHLAND SUNDAY NIGHT AND MONDAY MORNING...ESPECIALLY ALONG AND
NEAR THE GOGEBIC RANGE IN IRON COUNTY DUE TO THE LAKE ENHANCED AND
LAKE EFFECT SNOW SHOWERS. THE GOGEBIC RANGE COULD SEE UP TO A COUPLE
INCHES OF SNOW.
SEASONABLE TEMPERATURES IN THE UPPER 20S AND LOW 30S MONDAY ARE
EXPECTED MONDAY. THERE SHOULD BE A WARMING TREND FOR THE MIDDLE OF
THE WEEK AS SOUTHERLY WINDS DEVELOP AHEAD OF LOW PRESSURE MOVING
INTO THE WESTERN AND NORTHERN PLAINS. THE WARMING TREND WILL LIKELY
CULMINATE WEDNESDAY WITH HIGHS IN THE UPPER 30S AND LOW 40S. THERE
COULD BE SOME LIGHT RAIN AND SNOW WEDNESDAY THROUGH THURSDAY AHEAD
AND WITH THE PASSAGE OF A COLD FRONT. TEMPERATURES SHOULD BE NEAR
NORMAL FOR THE SECOND HALF OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1143 PM CST FRI NOV 15 2013
AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL
COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY
IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS
OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY
MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT
IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP
DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN
WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 44 40 44 24 / 70 70 50 30
INL 44 36 38 21 / 10 60 60 40
BRD 47 39 43 23 / 60 40 30 10
HYR 46 42 47 27 / 70 60 60 40
ASX 48 43 47 29 / 80 60 60 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...GROCHOCINSKI
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1230 AM CST SAT NOV 16 2013
.UPDATE...
ISSUED AT 1227 AM CST SAT NOV 16 2013
REMOVED THE MENTION OF LIGHT RAIN ALONG THE BORDERLAND AS THE RAIN
HAS MOVED INTO CANADA. ALSO REMOVED THE MENTION OF FOG FOR THE
OVERNIGHT AS DEWPOINT DEPRESSIONS ARE LARGE AND THE FOG AT CKC HAS
DISSIPATED. ALSO REMOVED THE MENTION OF DRIZZLE WITH A LACK OF ANY
FORCING NEARBY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY AFTERNOON)
ISSUED AT 345 PM CST FRI NOV 15 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL
FOR PATCHY FOG AND DRIZZLE TONIGHT AND EARLY SATURDAY
MORNING...AND THE RAIN SHOWERS EXPECTED TO DEVELOP TOMORROW MID TO
LATE MORNING FROM SOUTH TO NORTH AND PERSIST THROUGH THE
AFTERNOON. HAVE ALSO ADDED MENTION OF ISOLATED THUNDERSTORMS OVER
PARTS OF NW WISCONSIN IN THE LATE AFTERNOON.
DEEP CYCLONIC FLOW IN PLACE ACROSS MUCH OF THE CENTRAL CONUS TODAY
WITH A COUPLE SHRT WVS RIDING E/NEWD THROUGH THE NRN ROCKIES AND
NRN PLAINS. A SFC LOW IS DEVELOPING ALONG THE FRONT RANGE OF THE
ROCKIES AS A WEAK WARM FRONT EXTENDS EWD THROUGH NE INTO IA. THIS
FRONT WILL LIFT NWD AND COMBINE WITH MODEST WAA/MOISTURE TRANSPORT
FROM THE SOUTH AND A FAST MOVING UPPER S/W TO PRODUCE VERY LIGHT
PRECIP ACROSS THE NORTHLAND. ABOVE 600MB THE ATMOSPHERE WILL
BECOME NEARLY SATURATED. HOWEVER...A FAIRLY DEEP MID-LVL LAYER
WILL REMAIN DRY THROUGH MUCH OF THE NIGHT. AS THE NEAR SFC LAYER
COOLS AND SATURATES...AND SOME OF THE MOISTURE WORKS ITS WAY DOWN
THROUGH THE COLUMN...PATCH DRIZZLE WILL BE POSSIBLE. AT THIS TIME
THE MOST FAVORABLE LOCATION OF PRECIP IS DIFFICULT TO NAIL
DOWN...SO BASICALLY HAVE A BROAD AREA OF PATCHY FOG AND DRIZZLE.
THE SUSTAINED SOUTH WINDS AROUND 5 TO 10 MPH WILL INHIBIT
WIDESPREAD FOG FROM FORMING. HOWEVER...A STRONG INVERSION AND
PLENTY OF MOISTURE IN THE LOW LEVELS WILL BOTH SUPPORT FOG
FORMATION.
THE MAIN AREA OF LOW PRESSURE AT THE SFC WILL EVENTUALLY LIFT TO
THE NE INTO THE DAKOTAS AND SWRN MN DURING THE DAY SATURDAY AND
DRAW UP AN EVEN RICHER SUPPLY OF WARM MOIST AIR FROM THE SOUTH.
THIS AIR MASS WILL ALLOW FOR SLIGHT DESTABILIZATION OVER PARTS OF
NW WI LATE SAT AFTERNOON. HAVE ADDED ISOLATED THUNDERSTORMS FOR
THIS AREA FOR A FEW HOURS. OTHERWISE...PRECIP WILL BE ALL RAIN
WITH AMTS AROUND A QUARTER TO A THIRD OF AN INCH...WITH THE
HIGHEST AMOUNTS ACROSS THE ERN HALF OF THE FORECAST AREA.
TEMPERATURES WILL REMAIN VERY MILD DURING THE NEXT 24 HOURS...WITH
LOWS TONIGHT DROPPING INTO THE MID TO UPPER 30S...AND HIGHS
TOMORROW IN THE 40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CST FRI NOV 15 2013
WIDESPREAD PRECIPITATION WILL CONTINUE INTO SATURDAY NIGHT...BEFORE
GRADUALLY DECREASING FROM SOUTHWEST TO NORTHEAST. THIS WILL HAPPEN
BEFORE A COMPLEX SURFACE LOW DEVELOPS OVER THE REMAINDER OF THE
WEEKEND...WITH PRECIPITATION INCREASING ONCE AGAIN. THE SYSTEM IS
FAIRLY COMPLEX...WITH THE LOW PRESSURE SYSTEM BASICALLY EVOLVING
INTO A MAJOR SURFACE LOW RIGHT OVER OUR REGION. BY LATE SUNDAY... AN
INTENSE SURFACE LOW WILL BE LOCATED OVER THE EASTERN LAKE SUPERIOR
REGION. THE LOW WILL STRENGTHEN EVEN FURTHER ON SUNDAY NIGHT AND
MONDAY...AS IT LIFTS TO NEAR JAMES BAY BY 12Z MONDAY. THE ECMWF HAS
IT DROPPING TO A 975 MB LOW AT THAT TIME. AS THE WEEKEND WEARS
ON...WE WILL BE LOOKING AT SWITCH TO ALL SNOW...AND A DRAMATIC
INCREASE IN WIND. GALES ARE DISTINCTLY POSSIBLE OVER LAKE
SUPERIOR...WITH GUSTY WINDS INLAND AS WELL. DRY HIGH PRESSURE WILL
THEN BUILD INTO THE REGION FROM MONDAY INTO WEDNESDAY...WITH
TEMPERATURES MODERATING CONSIDERABLY BY MIDWEEK. A WEAK LOW PRESSURE
SYSTEM AND UPPER LEVEL SHORTWAVE WILL SET OFF SOME LIGHT
PRECIPITATION FROM WEDNESDAY NIGHT INTO THURSDAY. BY FRIDAY...THERE
IS MAJOR DISAGREEMENT AMONGST THE OPERATIONAL MODEL SET...WITH THE
GFS BRINGING A MAJOR STORM SYSTEM TO THE WESTERN GREAT LAKES. THE
ECMWF ON THE OTHER HAND...BRINGS DRY AND QUIET WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1143 PM CST FRI NOV 15 2013
AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL
COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY
IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS
OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY
MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT
IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP
DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN
WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 44 40 43 23 / 60 60 60 40
INL 43 36 38 21 / 30 70 60 40
BRD 47 38 42 23 / 50 30 40 20
HYR 45 43 47 26 / 70 60 70 40
ASX 47 43 47 28 / 70 60 70 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...BJT
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 PM CST FRI NOV 15 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY AFTERNOON)
ISSUED AT 345 PM CST FRI NOV 15 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE POTENTIAL
FOR PATCHY FOG AND DRIZZLE TONIGHT AND EARLY SATURDAY
MORNING...AND THE RAIN SHOWERS EXPECTED TO DEVELOP TOMORROW MID TO
LATE MORNING FROM SOUTH TO NORTH AND PERSIST THROUGH THE
AFTERNOON. HAVE ALSO ADDED MENTION OF ISOLATED THUNDERSTORMS OVER
PARTS OF NW WISCONSIN IN THE LATE AFTERNOON.
DEEP CYCLONIC FLOW IN PLACE ACROSS MUCH OF THE CENTRAL CONUS TODAY
WITH A COUPLE SHRT WVS RIDING E/NEWD THROUGH THE NRN ROCKIES AND
NRN PLAINS. A SFC LOW IS DEVELOPING ALONG THE FRONT RANGE OF THE
ROCKIES AS A WEAK WARM FRONT EXTENDS EWD THROUGH NE INTO IA. THIS
FRONT WILL LIFT NWD AND COMBINE WITH MODEST WAA/MOISTURE TRANSPORT
FROM THE SOUTH AND A FAST MOVING UPPER S/W TO PRODUCE VERY LIGHT
PRECIP ACROSS THE NORTHLAND. ABOVE 600MB THE ATMOSPHERE WILL
BECOME NEARLY SATURATED. HOWEVER...A FAIRLY DEEP MID-LVL LAYER
WILL REMAIN DRY THROUGH MUCH OF THE NIGHT. AS THE NEAR SFC LAYER
COOLS AND SATURATES...AND SOME OF THE MOISTURE WORKS ITS WAY DOWN
THROUGH THE COLUMN...PATCH DRIZZLE WILL BE POSSIBLE. AT THIS TIME
THE MOST FAVORABLE LOCATION OF PRECIP IS DIFFICULT TO NAIL
DOWN...SO BASICALLY HAVE A BROAD AREA OF PATCHY FOG AND DRIZZLE.
THE SUSTAINED SOUTH WINDS AROUND 5 TO 10 MPH WILL INHIBIT
WIDESPREAD FOG FROM FORMING. HOWEVER...A STRONG INVERSION AND
PLENTY OF MOISTURE IN THE LOW LEVELS WILL BOTH SUPPORT FOG
FORMATION.
THE MAIN AREA OF LOW PRESSURE AT THE SFC WILL EVENTUALLY LIFT TO
THE NE INTO THE DAKOTAS AND SWRN MN DURING THE DAY SATURDAY AND
DRAW UP AN EVEN RICHER SUPPLY OF WARM MOIST AIR FROM THE SOUTH.
THIS AIR MASS WILL ALLOW FOR SLIGHT DESTABILIZATION OVER PARTS OF
NW WI LATE SAT AFTERNOON. HAVE ADDED ISOLATED THUNDERSTORMS FOR
THIS AREA FOR A FEW HOURS. OTHERWISE...PRECIP WILL BE ALL RAIN
WITH AMTS AROUND A QUARTER TO A THIRD OF AN INCH...WITH THE
HIGHEST AMOUNTS ACROSS THE ERN HALF OF THE FORECAST AREA.
TEMPERATURES WILL REMAIN VERY MILD DURING THE NEXT 24 HOURS...WITH
LOWS TONIGHT DROPPING INTO THE MID TO UPPER 30S...AND HIGHS
TOMORROW IN THE 40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 345 PM CST FRI NOV 15 2013
WIDESPREAD PRECIPITATION WILL CONTINUE INTO SATURDAY NIGHT...BEFORE
GRADUALLY DECREASING FROM SOUTHWEST TO NORTHEAST. THIS WILL HAPPEN
BEFORE A COMPLEX SURFACE LOW DEVELOPS OVER THE REMAINDER OF THE
WEEKEND...WITH PRECIPITATION INCREASING ONCE AGAIN. THE SYSTEM IS
FAIRLY COMPLEX...WITH THE LOW PRESSURE SYSTEM BASICALLY EVOLVING
INTO A MAJOR SURFACE LOW RIGHT OVER OUR REGION. BY LATE SUNDAY... AN
INTENSE SURFACE LOW WILL BE LOCATED OVER THE EASTERN LAKE SUPERIOR
REGION. THE LOW WILL STRENGTHEN EVEN FURTHER ON SUNDAY NIGHT AND
MONDAY...AS IT LIFTS TO NEAR JAMES BAY BY 12Z MONDAY. THE ECMWF HAS
IT DROPPING TO A 975 MB LOW AT THAT TIME. AS THE WEEKEND WEARS
ON...WE WILL BE LOOKING AT SWITCH TO ALL SNOW...AND A DRAMATIC
INCREASE IN WIND. GALES ARE DISTINCTLY POSSIBLE OVER LAKE
SUPERIOR...WITH GUSTY WINDS INLAND AS WELL. DRY HIGH PRESSURE WILL
THEN BUILD INTO THE REGION FROM MONDAY INTO WEDNESDAY...WITH
TEMPERATURES MODERATING CONSIDERABLY BY MIDWEEK. A WEAK LOW PRESSURE
SYSTEM AND UPPER LEVEL SHORTWAVE WILL SET OFF SOME LIGHT
PRECIPITATION FROM WEDNESDAY NIGHT INTO THURSDAY. BY FRIDAY...THERE
IS MAJOR DISAGREEMENT AMONGST THE OPERATIONAL MODEL SET...WITH THE
GFS BRINGING A MAJOR STORM SYSTEM TO THE WESTERN GREAT LAKES. THE
ECMWF ON THE OTHER HAND...BRINGS DRY AND QUIET WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1143 PM CST FRI NOV 15 2013
AN AREA OF LOW PRESSURE...WAA AND MOISTURE ADVECTION WILL ALL
COMBINE TO GRADUALLY LOWER CEILINGS THROUGH THE PERIOD TO MAINLY
IFR. THE RAP WAS DOING A DECENT JOB DEPICTING THE MVFR CEILINGS
OVER MO/IL...AND BRINGS THEM NORTH LATE TONIGHT INTO SATURDAY
MORNING AND A LLJ. THERE MAY BE SOME LOW VFR CEILINGS...3500-5000FT...THAT
IMPACT KDLH/KHYR LATE TONIGHT AS WELL. RAIN/DRIZZLE WILL DEVELOP
DURING THE DAY SATURDAY ALONG WITH THE LOWERING CEILINGS. THE RAIN
WILL BE MOST LIKELY OVER EASTERN AREAS OF THE NORTHLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 39 44 40 43 / 10 60 60 60
INL 37 43 36 38 / 30 30 70 60
BRD 38 47 38 42 / 10 50 30 40
HYR 39 45 43 47 / 10 70 60 70
ASX 41 47 43 47 / 10 70 60 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BJT
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1226 AM EST SAT NOV 16 2013
.SYNOPSIS...
A WARM FRONT AND COASTAL TROUGH WILL BRING SHOWERS OVERNIGHT.
ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND WITH
THE RISK FOR SHOWERS INCREASING AGAIN LATE SUNDAY INTO MONDAY AS A
COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL CROSS THE AREA
MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER CONDITIONS THROUGH
MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 12:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
I`VE GOT TO SAY...THIS FORECAST ISN`T WORKING OUT LIKE I HAD
HOPED. THE 00Z CHARLESTON SOUNDING SHOWS PRECIPITABLE WATER HAS
RISEN TO NEARLY 1.3 INCHES...BUT ALSO SHOWS SEVERAL 3000-5000 FT
THICK DRY LAYERS LOCATED RIGHT IN THE ZONE I WOULD EXPECT THE BEST
ISENTROPIC LIFT TO BE OCCURRING. THE 00Z NAM INITIALIZED QUITE
WELL VERSUS THE CHARLESTON THERMAL/MOISTURE PROFILE AND HAS REALLY
TONED DOWN ITS RAINFALL POTENTIAL THROUGH 12Z. THE 18Z GFS WAS FAR
TOO WET AND SHOWS TOO MUCH MOISTURE THROUGHOUT THE 700-400 MB
LAYER VERSUS THE CHARLESTON SOUNDING. THE LATEST HRRR ALSO IS NOT
CAPTURING TRENDS WELL AND IS BEING IGNORED.
CHANGES WITH THIS UPDATE INCLUDE CUTTING POPS BACK TO 40-50 PERCENT
FOR THE REMAINDER OF THE NIGHT AND SLASHING QPF FORECASTS TO AROUND
0.05 INCHES. WHILE THE LOCATION AND DEGREE OF ISENTROPIC LIFT HAS
PROBABLY BEEN WELL-FORECAST BY THE MODELS ALL ALONG...DRY LIFT
DOESN`T YIELD RAINFALL. BREAKS HAVE EVEN OPENED IN THE OVERCAST DECK
NEAR GEORGETOWN...MYRTLE BEACH AND CONWAY IN THE PAST HOUR. :(
AN INVERTED TROUGH JUST OFFSHORE IS THE SURFACE FEATURE WE ARE
WATCHING THIS EVENING. IT EXTENDS NORTH FROM A WEAK LOW JUST EAST OF
JACKSONVILLE FL. IN THE UPPER LEVELS A SHORTWAVE TROUGH ACROSS THE
SOUTHERN AND CENTRAL APPALACHIANS WILL SWEEP OFFSHORE AFTER
MIDNIGHT. A PUSH OF WESTERLY MID-LEVEL WINDS BEHIND THIS FEATURE
SHOULD HELP NUDGE THE SURFACE TROUGH FARTHER OFFSHORE AS WELL. OUR
LOW LEVEL WINDS WILL BECOME QUITE LIGHT AS THE TROUGH SHIFTS
OFFSHORE LATE...WITH LITTLE OPPORTUNITY FOR THE CHILLIER AIR IN THE
MOUNTAINS TO ADVECT DOWN TOWARD THE COAST.
OVERNIGHT LOW TEMPERATURES ARE STILL EXPECTED TO RANGE FROM THE MID
50S ON THE COAST TO AROUND 50 ON THE INTERSTATE 95 CORRIDOR. THIS IS
ON THE HIGH END OF MOS GUIDANCE BUT SEEMS REASONABLE GIVEN
PREDOMINANTLY CLOUDY SKIES AND NO SUBSTANTIAL COLD ADVECTION EXPECTED
THROUGH DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BE PRESENT OFFSHORE ON
SAT. THIS TROUGH WILL LIFT N AND THEN DISSIPATE THROUGH SAT NIGHT.
EXPECT ANY LIGHT PRECIPITATION TO BE ENDING DURING SAT. INLAND
AREAS SHOULD SEE AN END TO THE SHOWERS IN THE MORNING. SHOWERS MAY
LINGER ALONG THE COAST INTO THE AFTERNOON...ESPECIALLY ACROSS THE
CAPE FEAR COAST IN CLOSEST PROXIMITY TO THE TROUGH. MOISTURE
PROFILES AND MODEL SOUNDINGS SHOW A GRADUAL DECREASE IN MOISTURE
ON SAT. A PRONOUNCED NEAR SURFACE INVERSION LINGERS INTO SAT
MORNING...BUT EVENTUALLY THE LOW-LEVEL MOISTURE DOES SCOUR OUT.
THIS SHOULD ALLOW PARTIAL SUNSHINE TO DEVELOP SAT AFTERNOON WITH
THE GREATEST CLOUD COVER LIKELY PERSISTING ACROSS THE CAPE FEAR
REGION. A DEEPENING AND STRENGTHENING S TO SW FLOW WILL ENVELOP
THE AREA SUN AND SUN NIGHT. ANOTHER PRONOUNCED LOW-LEVEL INVERSION
IS EXPECTED TO DEVELOP SAT NIGHT AND THIS WILL LINGER INTO SUN
MORNING. THIS INVERSION SHOULD ALLOW LOW STRATUS TO DEVELOP AND
PERSIST INTO A GOOD PORTION OF SUN MORNING. AT THE SAME TIME...MID
AND HIGH LEVEL MOISTURE WILL BE INCREASING AS PRECIPITABLE WATER
VALUES CLIMB TO ABOUT AN INCH AND THREE- QUARTERS SUN EVE AND
NIGHT. THUS...SUN LOOKS TO BE A RATHER CLOUDY DAY THROUGHOUT. THE
COLUMN BECOMES SUFFICIENTLY MOIST IF NOT SATURATED THROUGH A DEEP
LAYER SUN NIGHT AND WILL SHOW POPS INCREASING TO LIKELY OVERNIGHT.
IT IS POSSIBLE SHOWERS DEVELOP EARLIER ON SUN...BUT MOST OF THE
RAINFALL IS EXPECTED SUN NIGHT AND POSSIBLY INTO MON. AT THIS TIME
WILL KEEP MENTION OF ONLY SHOWERS. HOWEVER...INCREASING CAPE
VALUES WERE NOTED AND SO THERE IS A SMALL CHANCE FOR A RUMBLE OF
THUNDER ALTHOUGH AT THIS TIME...FEEL THE RISK WILL BE CONFINED TO
OFFSHORE AREAS WHERE BAROCLINICITY WILL BE HIGHEST.
TEMPS WILL BE A DEG OR TWO ABOVE NORMAL BY DAY AS DEVELOPING WARM
AIR ADVECTION IS MODERATED BY CONSIDERABLE CLOUD COVER...ESPECIALLY
ON SUN. THIS WILL PUT HIGH TEMPS MAINLY IN THE LOWER TO PERHAPS MID
70S. LOW TEMPS WILL HOWEVER BE WELL ABOVE NORMAL...IN THE 50S SAT
NIGHT AND IN THE 60S SUN NIGHT. THE NORMAL LOW TEMPS FOR MID NOV ARE
IN THE MID 40S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...THE MID LEVEL PATTERN WILL CONSIST OF MAINLY A
FLAT/ZONAL FLOW BEYOND MONDAY WHEN A WEAKENING TROUGH WILL USHER
THROUGH ANOTHER FAST MOVING FRONT. I DID MAINTAIN THE LIKELY POPS
WITH THIS FEATURE FOR ALL OF MONDAY...AT LEAST THROUGH 0000 UTC
TUESDAY AS THERE REMAINS JUST ENOUGH DISAGREEMENT IN TIMING BETWEEN
THE FASTER GFS SOLUTIONS AND SLOWER WPC PREFERRED ECMWF ENSEMBLE
MEAN. WEEKEND SHIFTS SHOULD BE ABLE TO FINE TUNE TIMING.
BEYOND THIS...HIGH PRESSURE BUILDS IN BUT THE COLD AIR ADVECTION IS
DELAYED SOMEWHAT AS 850MB TEMPERATURES DON/T BOTTOM OUT UNTIL
WEDNESDAY AFTERNOON. OVERALL TEMPERATURE TRENDS ARE SOMEWHAT BELOW
NORMAL WITH WEDNESDAY AND THURSDAY THE COOLEST WARMING A BIT FRIDAY
BASICALLY DUE TO AIR MASS MODIFICATION AND THE DEVELOPMENT OF A
COASTAL TROUGH. TUESDAY TEMPERATURES ARE RIGHT AROUND NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...RADAR IMAGERY INDICATES THE SHOWERS ASSOCIATED WITH A
COASTAL TROUGH HAVE REMAINED OFFSHORE TONIGHT. PRIMARILY VFR CIGS
PREVAIL ACROSS THE AREA AS THE MODELS SEEM TO HAVE OVER-ESTIMATED
THE AVAILABLE MOISTURE FOR PCPN. BASED ON THESE TRENDS...HAVE CUT
BACK PCPN IN THE TAFS TO ONLY MENTION VCSH INTO THE MORNING HOURS.
CALM TO LIGHT WINDS ARE EXPECTED OVERNIGHT...BUT THE CLOUD COVER
SHOULD KEEP VSBYS FROM SIGNIFICANTLY DROPPING. CANNOT RULE OUT SOME
MVFR VSBYS/TEMPO IFR CIGS BEFORE DAYBREAK...BUT AGAIN THE POOR
PERFORMANCE OF THE MODELS WITH REGARDS TO THE MOISTURE PROFILES
LOWERS MY CONFIDENCE. DO NOT ANTICIPATE ANYTHING WORSE THAN MVFR
CONDITIONS OVERNIGHT ATTM. EXPECT MAINLY VFR DURING THE DAYTIME WITH
E-NE WINDS AROUND 5 KTS. FOG COULD BE AN ISSUE EARLY SUNDAY...BUT
ANY VSBY IMPACTS WILL LIKELY OCCUR AFTER THE VALID TAF PERIOD.
EXTENDED OUTLOOK...MVFR/IFR FOG POSSIBLE ON SUNDAY MORNING. EXPECT
SHOWERS AND PERIODS OF MVFR/IFR EARLY MONDAY WITH A COLD FRONT.
STRATUS POSSIBLE ALONG THE COAST ON WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
AN INVERTED SURFACE TROUGH EXTENDS SOUTH-TO-NORTH ACROSS THE
CAROLINA COASTAL WATERS. ITS EXACT LOCATION IS TOUGH TO PIN DOWN
WITH SPARSE OBSERVATIONS...BUT BASED ON WIND DIRECTIONS AT THE
BEACHES AND AT THE FRYING PAN SHOALS BUOY PROBABLY LIES 10-15
MILES EAST OF CAPE FEAR AND 40-45 MILES EAST OF MYRTLE BEACH AND
GEORGETOWN. THIS TROUGH SHOULD WEAKEN AND SHIFT EAST AND FARTHER
OFFSHORE OVERNIGHT AS AN UPPER LEVEL TROUGH PASSES OVERHEAD AFTER
MIDNIGHT.
WINDS EAST OF THE TROUGH AXIS ARE GENERALLY E-NE IN THE 8-12 KNOT
RANGE...WHILE EAST OF THE TROUGH OVER THE OFFSHORE WATERS THEY ARE
SOUTHEAST NEAR 15 KNOTS AT THE FRYING PAN SHOALS BUOY WITH
GUSTS TO 17 KNOTS. SEAS HAVE BUILT TO 4 FT OFFSHORE AND TO 2.5 FEET
AT THE BUOY JUST SOUTH OF CAPE FEAR.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...A COASTAL TROUGH WILL BISECT THE WATERS ON
SAT. THIS TROUGH WILL LIFT N OF THE AREA SAT NIGHT AND DISSIPATE.
A COLD FRONT WILL APPROACH FROM THE W SUN AND SUN NIGHT. THE
APPROACH OF THIS FRONT WILL GRADUALLY TIGHTEN WHAT WILL OTHERWISE
BE A SLACK GRADIENT THIS WEEKEND. THE STRONGEST WINDS ARE EXPECTED
SUN NIGHT. THE WINDS WILL BE LIGHT ENE TO E SAT. THE DIRECTION
WILL VEER TO SE SAT NIGHT AND TO S ON SUN. WINDS WILL EVENTUALLY
COME AROUND TO SW MON MORNING. WIND SPEEDS WILL REACH UP TO 15 TO
20 KT SUN NIGHT. SEAS WILL BE 2 TO 3 FT SAT THROUGH SUN AND THEN
BUILD TO 4 TO POSSIBLY 5 FT SUN NIGHT. AN 8 TO 10 SECOND SE SWELL
WILL BECOME MORE SIGNIFICANT LATE SUN AND SUN NIGHT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...THE MAIN FEATURE FOR THE MARINE COMMUNITY WILL
BE THE FRONT THAT MOVES ACROSS THE WATERS EARLY IN THE PERIOD. THE
TIMING REMAINS CONFIDENCE CHALLENGED BUT FOR NOW IT LOOKS LIKE A
LATE AFTERNOON WIND SHIFT FROM THE SOUTHWEST TO WEST. NOT THE MOST
DYNAMIC OF SYSTEMS SO WINDS WILL TAKE SOME TIME...BY TUESDAY MORNING
TO REACH MARGINAL SMALL CRAFT CRITERIA WITH A 20-25 KNOT RANGE.
WINDS HAVE A GOOD CHANCE TO STAY ELEVATED AS COLD AIR ADVECTION LAGS
WELL BEHIND THE FRONT AND WILL PROBABLY HOVER AROUND 20 KNOTS
THROUGH THE END OF THE PERIOD. SEAS WILL BUILD WITH THE WINDS FROM
INITIAL VALUES OF 2-4 FEET TO 4-7 FEET BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1245 AM EST SAT NOV 16 2013
.SYNOPSIS...
DISTURBANCE ALOFT EXITING OVERNIGHT. WARMING TREND THROUGH
THE WEEKEND. STRONG COLD FRONT CROSSES SUNDAY NIGHT. IN FAST FLOW
ALOFT...GUSTY SHOWERS LIKELY. TURNING COLDER MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...
ENDED THE POPS QUICKER IN THE OVERNIGHT PERIOD PER LOCAL WRF
MODELS AND THE HRRR MODEL. RAIN WEST OF THE TUG FORK RIVER IS MORE
SCATTERED IN NATURE...AND WILL SEE THIS TREND MOVING INTO THE WEST
VIRGINIA COAL FIELDS IN THE NEXT COUPLE OF HOURS.
PREVIOUS DISCUSSION...
RADAR AND SATELLITE IMAGES INDICATE SHOWERS STRUGGLING TO REACH
THE GROUND ACROSS EASTERN KY THIS AFTERNOON. VERY DRY AIR MASS
REMAINS IN PLACE PRODUCING VIRGA FOR THE MOST PART. BELIEVE...THE
COLUMN WILL CONTINUE TO MOISTEN...MAKING FEW OF THESE LIGHT
SHOWERS TO AFFECT THE EASTERN MOUNTAINS LATER THIS EVENING AND
TONIGHT.
BREEZY FLOW WILL SUBSIDE LATER TONIGHT AND BECOME MORE SOUTHERLY
OVERNIGHT. ADDITIONAL LIGHT SHOWERS WILL BE POSSIBLE ACROSS THE
SOUTHERN COAL FIELDS OF WV EARLY SATURDAY.
KEPT POPS REACHING LIKELY THIS EVENING ACROSS THE SOUTHEAST HALF
OF OUR CWA. MINOR CHANGES TO TEMPERATURES NEEDED.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT ON THE STRONG COLD FRONT THAT RAPIDLY
MOVES ACROSS SUNDAY EVENING AND SUNDAY NIGHT. GIVEN THE ASSOCIATED
NEGATIVELY TILTED UPPER TROUGH SWINGING UP THROUGH THE GREAT LAKES
WITH A DEEPENING SURFACE LOW...THE MODEL TRENDS OF SPEEDING THE
FRONT UP EVEN MORE SEEMS REASONABLE. THE CMC IS EVEN FASTER THAN THE
OTHER SWEET OF MODELS...WHICH ONE CANNOT RULE OUT...BUT WILL STICK
WITH THE VAST MAJORITY OF GUIDANCE WITH THE TIMING. THIS BRINGS THE
FRONT TO THE OHIO RIVER SUNDAY EVENING AND EXITING THE MOUNTAINS
AFTER MIDNIGHT SUNDAY NIGHT...WELL BEFORE DAWN MONDAY.
IN THIS SYNOPTIC SCENARIO...THE LOW LEVEL WINDS WILL BE QUITE STRONG
AND GUSTY MAINLY ALONG AND JUST AHEAD OF THE FRONT...WITH MODEL
FORECASTS OF 60 TO 65 KNOTS OF SOUTHWEST WINDS AT 850MB PRECEDING
THE FRONT. BEING CLOSER TO THE SURFACE LOW...THESE STRONGEST WINDS
WITH THIS SYSTEM WILL BE ACROSS THE NORTHWEST THIRD OF THE AREA
SUNDAY AFTERNOON AND SUNDAY EVENING. THERE WILL ALSO BE A BAND OF
SHOWERS AND A FEW THUNDERSTORMS AS THE FRONT PASSES THROUGH. GIVEN
ALL OF THIS...THE BEST CHANCE OF STRONG AND GUSTY WINDS...POSSIBLY
DAMAGING WINDS...WILL BE IN THE CONVECTION ALONG AND JUST AHEAD OF
THE FRONT AND ESPECIALLY OVER NORTHWEST PORTIONS OF THE AREA. SPC
ALSO HAS A SLIGHT RISK OF SEVERE STORMS SNEAKING IN FROM THE WEST
SUNDAY EVENING WITH THE FRONT...WITH THE MAIN THREAT BEING DAMAGING
WINDS. THIS IS HIGHLIGHTED IN THE HAZARDOUS WEATHER OUTLOOK PRODUCT.
AFTER A DRY AND MILD SATURDAY NIGHT...SUNDAY ITSELF WILL FEATURE A
LOT OF CLOUDS AND SCATTERED SHOWERS IN THE WARM ADVECTION AND MOIST
SOUTHERLY INFLOW WELL AHEAD OF THE FRONT ITSELF. WHILE CLOUDS WILL
HELP LIMIT MIXING WITH THE INCREASING LOW LEVEL WINDS...ONE CANNOT
RULE OUT AN ISOLATED DAMAGING GUST IN A SHOWER SUNDAY AFTERNOON...
ESPECIALLY NORTHWEST PORTIONS OF THE AREA FOR THE REASONS MENTIONED
ABOVE. LOOK FOR TEMPS SUNDAY TO BE WELL ABOVE NORMAL...AROUND 70...
DESPITE THE CLOUDS.
FRONT BLASTS THRU SUNDAY NIGHT WITH WESTERLY WINDS BRINGING IN A
NICE DRY SLOT BY MONDAY MORNING. LOOK FOR A DRY AND A MODESTLY
COOLER DAY MONDAY AS MOST OF THE COLD ADVECTION REMAINS NORTH OF US.
LATER IN THE DAY MONDAY...AS WINDS DO TURN MORE NORTHWESTERLY...LOOK
FOR INCREASED COLD ADVECTION AND UPSLOPE TO BRING A LOW CHANCE OF
RAIN SHOWERS IN THE NORTHERN WEST VIRGINIA MOUNTAINS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
GENERALLY QUIET IN THE EXTENDED. SOME SNOW SHOWERS POSSIBLE ACROSS
THE NORTHERN ZONES MONDAY NIGHT AS THE UPPER FLOW TURNS
NORTHWESTERLY BRIEFLY. MAINLY ZONAL FLOW MID WEEK WITH SOME UPPER
RIDGING TAKING HOLD BY WEEKS END. A CHILLY AIRMASS WILL MODIFY TO
NEAR NORMAL BY WEEKS END.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
DISTURBANCE ALOFT EXITING AT 06Z SATURDAY. IT HAS LEFT THE LOW
LEVELS IN HTS-CRW-BKW ON SOUTH SATURATED. HAVE CEILINGS LOWERING
OVER SOUTHERN MOUNTAINS INCLUDING BKW AT TIMES TO AOB 1 THSD FT BKN
IN STRATUS THEN LIFTING AFTER 14Z. WILL HOLD LOWLANDS AROUND HTS-CRW
WITHOUT THAT LOW CEILING FORMING...THINKING MORE SCATTERED AS HIGHER
CLOUDS THIN 06Z TO 12Z.
FROM 14Z THROUGH THE DAY...HAVE LOWEST CEILINGS AROUND THE EASTERN
SLOPES INCLUDING POCAHONTAS COUNTY AT 1 TO 2 THSD FT BKN...ALSO SOME
2 THSD FT CEILINGS POSSIBLE IN NORTHEAST KENTUCKY AND SOUTHEAST IN
THE MOIST 925 MB SOUTHERLY FLOW. IN BETWEEN THOSE AREAS...FOR THE
WESTERN SLOPES...INCLUDING CRW-PKB-CKB HAVE CEILINGS HIGHER MOSTLY 3
TO 5 THSD FT BKN.
BY 06Z SUNDAY...CEILINGS REMAINING LOW ALONG THE EASTERN SLOPES WITH
SOME AOB 1 THSD FT BKN AND VSBY BLO 3 MILES IN FOG ACROSS HIGH
TERRAIN. TO THE WEEST...BY 06Z...SHOWERS MAY REACH INTO PORTIONS
OF SOUTHEAST OHIO WITH VSBY NEAR 5 MILES.
THE LOW LEVEL FLOW WILL START TO INCREASE 00Z TO 06Z SUNDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: IN SOUTHERN COUNTIES THROUGH 14Z...WITH LOW
LEVELS SATURATED FROM PREVIOUS LIGHT RAIN...SOME STRATUS CEILINGS
AOB 1 THSD FT COULD FORM IN THE WESTERN LOWLANDS AROUND HTS-CRW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 11/16/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H M M M H M M M H
HTS CONSISTENCY H H M M M M M M M M M H
BKW CONSISTENCY M M M M M M M L M M M M
EKN CONSISTENCY M H H H H H H H M M M H
PKB CONSISTENCY H H H H H H H H H M M H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z SUNDAY...
IFR IN STRATUS POSSIBLE ON THE EASTERN SLOPES OF THE WV MOUNTAINS
THROUGH 15Z SUNDAY MORNING...INCLUDING THE GREENBRIER VALLEY.
IN STRONG WIND FLOW AREA WIDE...IFR ALSO POSSIBLE IN GUSTY RAIN
SHOWERS SUNDAY AFTERNOON AND SUNDAY NIGHT...AHEAD OF...AND ALONG
COLD FRONT. EMBEDDED THUNDER POSSIBLE JUST AHEAD OF THE FRONT SUNDAY
EVENING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/ARJ/JMV/30
NEAR TERM...ARJ/26
SHORT TERM...JMV
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
332 AM CST SAT NOV 16 2013
.SHORT TERM...TODAY THROUGH MONDAY
WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA
EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE
SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST
THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID
LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO
WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER
SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST
SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT
TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF
PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO
SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW
PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS
STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW
CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH
DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY
GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL
THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY.
REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST
CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT
ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE
IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH
WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT
REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP
BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK.
ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY
MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS
CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE
INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE
DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT
PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD
THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN
BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE
MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS
HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS
TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST
UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST
CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER
MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT
THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY
WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD
BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY.
WILL CONTINUE TO MONITOR.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH
TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE
FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS
THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD
OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE
DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE
FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A
SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER
RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER
CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL.
THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION
BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW
WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT
FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW
ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG
BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12
HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES
STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS
STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH
OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS
POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE
EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW
MORNING...AS WELL.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT.
HOWEVER THERE IS ONE CAVEAT. SOME NEW SREF MEMBERS CONTINUE TO
BRING LOW CIGS/VSBYS NORTH TO NEAR KATY LATE TNT. THEREFORE WILL
PUT IN A MENTION OF IFR/MVFR CIGS LATE TNT AND SATURDAY MORNING
FOR KATY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
402 AM CST SAT NOV 16 2013
.DISCUSSION...
PATCHY FOG...LOCALLY DENSE IN A FEW SPOTS...WILL PERSIST THROUGH
MID MORNING BEFORE ERODING. DEEP MOISTURE REMAINS IN PLACE. NOT
MUCH IN THE WAY OF A LOW LEVEL FOCUS AND UPPER LEVEL SUPPORT BUT
THE MOISTURE LEVELS ARE SO HIGH THAT FEEL SOME SHOWERS WILL
DEVELOP DURING THE DAY. BOTH THE RAP AND TEXAS TECH WRF SHOW
SHOWERS DEVELOPING THIS AFTN SO WILL ADD 20 POPS BACK TO THE
FCST. OVERNIGHT LOWS ON SUN MORNING WILL BE UNSEASONABLY WARM AND
MINS WILL ONLY FALL INTO THE UPPER 60S. W-SW WINDS JUST OFF THE
SURFACE COUPLED WITH THE WARM START SHOULD YIELD MAX TEMPS IN THE
MID 80S. RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. FCST
SOUNDINGS ON SUNDAY SHOW AN ERODING CAP AND PWATS BETWEEN 1.6 AND
1.8 INCHES SO WILL MAINTAIN 20 POPS ON SUNDAY.
A COLD FRONT WILL CROSS SE TX ON MONDAY. GFS LOOKS A BIT FAST WITH
THIS FEATURE AND PREFER THE SLOWER NAM/ECMWF SOLN. MSTR POOLS
AHEAD OF THE BOUNDARY AND SCT SHRA/TSRA WILL BE POSSIBLE ALONG THE
COAST AND PARTS OF THE SOUTHERN CWA. AM CARRYING CHC POPS FOR THE
COAST ON MONDAY MORNING BUT FEEL THESE MIGHT BE A TAD LOW. MSTR
LEVELS NEVER REALLY DROP OFF THIS WEEK AND AN UPPER LEVEL
DISTURBANCE COULD BRING MORE SHOWERS ON TUESDAY AFTN. SW FLOW
ALOFT ON THURSDAY WILL BRING A DISTURBANCE ACROSS SE TX. THIS
FEATURE COUPLED WITH PWATS AROUND 1.6 INCHES SHOULD AGAIN YIELD
MORE PRECIP. MSTR ON THE BACKSIDE OF A RETREATING SURFACE RIDGE
WILL CONTINUE TO DRAW DEEPER MSTR INTO SE TX THU/FRI. A COLD FRONT
WILL CROSS SE TX ON FRI AND RAIN CHANCES WILL CONTINUE. A DEEP
UPPER LEVEL LOW WILL REMAIN WEST OF THE REGION THROUGH NEXT
WEEKEND. ISENTROPIC UPGLIDE WILL BE MAXIMIZED WITH NNE SFC WINDS
BEING OVERRUN BY SW WINDS ALOFT. NEXT WEEKEND LOOKS RAINY AND
KIND OF RAW. MAX TEMPS WILL STRUGGLE TO REACH 50 DEGREES IF THE
ECMWF VERIFIES. LEANED TOWARD THE ECMWF NEXT FRI-SUN BUT MODELS
DIFFER WITH TIMING AND RUN TO RUN CONSISTENCY HAS BEEN POOR. 43
&&
.CLIMATE...
RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. RECORDS FOR
SUNDAY NOV 17TH ARE THE FOLLOWING:
CURRENT RECORDS FORECAST
VALUES
IAH 84 - 1985 86
CLL 85 - 1921 86
&&
.MARINE...
LONG PERIOD SWELLS WERE OCCURRING AT BUOY 42019. MAY NEED TO UPGRADE
TO A SMALL CRAFT ADVISORY IF THESE CONTINUE AND WILL UPDATE IF
NEEDED. OTHERWISE...WINDS WILL GRADUALLY DECREASE LATER TODAY AND
TONIGHT AS A COLD FRONT MOVES TOWARD THE COAST. THE FRONT IS
EXPECTED TO PUSH OFF THE COAST MONDAY MORNING WITH INITIAL POST
FRONTAL WINDS OUT OF THE NORTH. THE MODELS ARE CONSISTENT WITH
MODERATE TO STRONG NORTHEAST WINDS DEVELOP MONDAY NIGHT AND TUESDAY.
AS HIGH PRESSURE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE
EASTERN SEABOARD...EXPECT SOUTHEAST WINDS TO DEVELOP BY WEDNESDAY.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 81 71 86 61 74 / 20 20 20 10 10
HOUSTON (IAH) 81 72 86 66 77 / 20 20 20 20 20
GALVESTON (GLS) 77 70 78 69 74 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1131 PM CST FRI NOV 15 2013
.AVIATION...
FOR THE 06Z TAFS...PRIMARY CONCERNS REMAIN THE SMALL POTENTIAL FOR
SHRA THROUGH 12Z...AND THE WINDS AFTER 12Z. THE THREAT FOR SHRA
APPEARS TO BE LIMITED TO JUST KAMA...PRIMARILY BETWEEN 09 AND 11Z.
THE EARLIER CONCERNS FOR DOWNBURSTS WITH SHRA AND VIRGA HAVE
DECREASED AS AN INVERSION HAS DEVELOPED...AND DEW POINT DEPRESSIONS
ARE MUCH SMALLER NOW. THUS...FEW IMPACTS ARE EXPECTED FROM ANY
SHOWERS.
WINDS STILL EXPECTED TO INCREASE DRAMATICALLY BETWEEN 15 AND 18Z. KAMA
AND KDHT SHOULD SEE WIND SPEEDS APPROACH 30G40KT THROUGH LATE
AFTERNOON. WILL WAIT ONE MORE TAF ISSUANCE BEFORE DECIDING ON AN AWW
AT KAMA...THOUGH AT THIS POINT...IT APPEARS LIKELY TO BE NEEDED.
STILL A SMALL THREAT THAT WITH THE STRONGEST WINDS BLOWING DUST COULD
REDUCE VISIBILITIES INTO THE MVFR RANGE. OTHERWISE...VFR CONDITIONS
ARE EXPECTED THROUGH THE TAF PERIOD.
JOHNSON
&&
.PREV DISCUSSION... /ISSUED 518 PM CST FRI NOV 15 2013/
AVIATION...
FOR THE 00Z TAFS...THE PRIMARY CONCERNS ARE THE POTENTIAL FOR SHRA
TONIGHT...AND WINDS TOMORROW. SHRA WILL BE POSSIBLE AFTER
03Z...THOUGH MORE LIKELY AFTER 06Z...ACROSS THE W AND S TX PANHANDLE.
COVERAGE WILL BE LIMITED...SO THERE IS NOT ENOUGH CONFIDENCE TO
INCLUDE ANYTHING MORE THAN VCSH AT THIS TIME. HOWEVER...IF A SHRA
DOES DIRECTLY IMPACT A TERMINAL...GIVEN VERY DRY LOW LEVELS...THERE
IS A THREAT FOR DRY DOWNBURSTS LEADING TO GUSTY AND VARIABLE WINDS.
TOMORROW...WINDS WILL INCREASE SHORTLY AFTER 15Z...APPROACHING
30G40KT. HOWEVER...THERE IS ONE CONCERN THAT CLOUDS WILL NOT CLEAR
OUT IN TIME TO ALLOW MAXIMUM MIXING. EVEN GRANTING THE CLOUDS ARE
SLOWER TO CLEAR OUT...AGREE WITH THE PREVIOUS SHIFT THAT A FEW GUSTS
NEAR 40KT ARE LIKELY AT KAMA AND KDHT. FOR NOW HOWEVER...WILL NOT
ISSUE AN AWW FOR THE WINDS TOMORROW IN CASE AN AWW WILL BE NEEDED
THIS EVENING DUE TO THE GUSTY WINDS WITH SHRA.
VFR CONDITIONS ARE EXPECTED WITH THE EXCEPTION OF A SMALL THREAT OF
DECREASED VISIBILITIES DUE TO BLOWING DUST IN THE STRONGEST WINDS.
JOHNSON
PREV DISCUSSION... /ISSUED 232 PM CST FRI NOV 15 2013/
DISCUSSION...
FORECAST CHALLENGES OVER THE NEXT 24 HOURS INCLUDE CHANCES FOR ANY
CONVECTION TONIGHT AND WIND ADVISORY PROSPECTS FOR SATURDAY. AGREE
WITH WFO LUBBOCK AS THE HRRR AND EVEN THE RUC SHOWING PRECIP MOVING
NORTH AND EAST OUT OF NEW MEXICO THIS EVENING THROUGH TONIGHT ACROSS
MAINLY PARTS OF THE TEXAS PANHANDLE. THIS CONVECTION ASSOCIATED WITH
A SHORTWAVE LOCATED OVER WESTERN AND SOUTHERN NEW MEXICO AND FORECAST
TO LIFT NORTH AND EAST INTO THE SOUTHWEST AND CENTRAL TEXAS PANHANDLE
AFTER 00Z AND 03Z SATURDAY. CONFIDENCE NOT HIGH ENOUGH TO MENTION
THUNDER...BUT WILL INTRODUCE ISOLATED SHOWERS FOR THE TONIGHT
PERIOD. CONSIDERABLE MID AND HIGH LEVEL CLOUDINESS TONIGHT INTO
SATURDAY MAY PUT A DAMPER ON MIXING THE STRONGER WINDS ALOFT AFTER
15Z TO 17Z SATURDAY...HOWEVER AGREE THAT WIND ADVISORY CRITERIA MAY
BE MET ON THE CAPROCK BY 18Z SATURDAY. CONFIDENCE JUST NOT HIGH
ENOUGH ON TIMING AND LOCATION TO ISSUE A WIND ADVISORY AT THIS TIME.
FEEL THAT A NARROW WINDOW OF WIND ADVISORY CRITERIA POSSIBLE BETWEEN
ABOUT 17Z AND 21Z SATURDAY...WITH WIND SPEEDS GRADUALLY DECREASING
THROUGH THE REMAINDER OF THE AFTERNOON.
COLD FRONT EXPECTED TO PUSH SOUTH AND WEST THROUGH THE PANHANDLES
DURING THE DAY SUNDAY BRINGING COOLER CONDITIONS EARLY NEXT WEEK.
MODERATING TEMPERATURES BY THE MIDDLE OF NEXT WEEK BEFORE ANOTHER
COLD FRONT MOVES THROUGH THE FORECAST AREA LATE NEXT WEEK. MEDIUM
RANGE MODELS INDICATING POSSIBLE PRECIP CHANCES BY THURSDAY NIGHT OR
FRIDAY MAINLY ACROSS THE EASTERN SECTIONS OF THE PANHANDLES AS AN
UPPER TROUGH APPROACHES FROM THE FOUR CORNERS AND SOUTHERN ROCKIES.
WILL HOLD OFF INTRODUCING ANY POPS IN THE THURSDAY TO FRIDAY TIME
FRAME...BUT WILL BUMP UP POPS TO AROUND 10 PERCENT OR SO.
SCHNEIDER
FIRE WEATHER...
MARGINAL ELEVATED FIRE WEATHER CONDITIONS WILL PERSIST UNTIL AROUND
SUNSET THIS EVENING WITH THE 20 FOOT WIND SPEEDS GRADUALLY SUBSIDING
BUT STILL REMAINING IN THE 15 TO 20 MPH RANGE WITH SOME HIGHER GUSTS.
20 FOOT DOWNSLOPING SOUTHWESTERLY WINDS WILL INCREASE AFTER MID TO
LATE MORNING TO AROUND 20 TO 30 MPH WITH HIGHER GUSTS AND MINIMUM
AFTERNOON HUMIDITIES FALLING TO NEAR 20 PERCENT. ALTHOUGH ONLY
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY...THE STRONG
WINDS ALONE MAY JUSTIFY ISSUING A FIRE DANGER STATEMENT FOR ELEVATED
FIRE WEATHER CONDITIONS. ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS
ARE NOT EXPECTED SUNDAY THROUGH LATE NEXT WEEK AS EITHER THE MINIMUM
AFTERNOON RELATIVE HUMIDITIES REMAIN AT OR ABOVE 20 PERCENT OR THE 20
FOOT WIND SPEEDS REMAIN BELOW 15 TO 20 MPH.
SCHNEIDER
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
16/02
AREA FORECAST DISCUSSION
NWS SPOKANE WA
927 PM PST Fri Nov 15 2013
.SYNOPSIS...
A strong weather system will spread rain and snow into most of the
region tonight and Saturday with accumulating snow in the
mountains as well as some northern valley locations. The weather
will trend slightly drier on Sunday into early Monday...except
near the Canadian border. A much wetter but warmer weather system
will move into the area late Monday and continue through Tuesday
and Wednesday.
&&
.DISCUSSION...
Looking at recent HRRR runs and some other later model guidance
felt it appropriate to delay the start of the wind advisory a few
hours to 10 PM PST rather than its earlier 7 PM start as the jet
is just a bit slow entering the area. /Pelatti
&&
.AVIATION...
06Z TAFs: Low pressure system dragging wet cold front through and
leaving a cold conditionally unstable airmass behind allow for a wet
and cluttered forecast with nuisance snow levels near elevations of
aviation sites. Thus the nuisance snowfall allows for low ceilings
and visibilities tonight and into tomorrow. Wind with the cold
front could cause nuisance low level wind shear at times as well and
allow for some gusty conditions at locations that mix these winds
down to the surface. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 33 36 27 40 31 42 / 100 60 10 40 40 10
Coeur d`Alene 33 36 25 38 29 41 / 100 90 20 50 50 20
Pullman 33 37 30 40 32 43 / 100 90 10 40 40 30
Lewiston 38 40 34 46 34 47 / 90 80 20 30 30 20
Colville 34 38 21 37 27 41 / 100 60 20 50 60 20
Sandpoint 33 36 24 37 30 40 / 100 100 40 70 70 50
Kellogg 31 33 26 35 27 39 / 100 100 70 50 60 40
Moses Lake 37 45 29 47 32 47 / 40 10 0 10 10 10
Wenatchee 35 43 30 43 33 46 / 10 10 0 10 10 10
Omak 30 40 26 39 30 43 / 20 10 0 30 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory until 10 AM PST Saturday for Coeur
d`Alene Area.
Winter Storm Warning until 4 AM PST Sunday for Central Panhandle
Mountains-Northern Panhandle.
Winter Weather Advisory until 4 PM PST Saturday for Lewis and
Southern Nez Perce Counties.
WA...Winter Weather Advisory until 4 PM PST Saturday for Northeast
Mountains-Okanogan Highlands.
Wind Advisory from 10 PM this evening to 7 AM PST Saturday for
Lower Garfield and Asotin Counties-Upper Columbia Basin-
Washington Palouse.
Winter Weather Advisory until 4 PM PST Saturday for Northeast
Blue Mountains.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
950 AM EST SAT NOV 16 2013
.DISCUSSION...
CANOPY OF MID AND HIGH CLOUD COVER CONTINUES TO STREAM ACROSS
CENTRAL FLORIDA FROM THE WEST. RUC13 SHOWS AN ELONGATED VORT IN THE
850-700 MB LAYER IN THE EASTERN GULF. HI RES VIS/IR SAT IMAGERY
SHOWS A SFC REFLECTION (NICE TWIST TO THE CLOUDS) IN THE EASTERN
GULF JUST NW OF NOAA BUOY 42003 WHICH IS MAINTAINING SHOWERS OVER
THE EASTERN GULF. ALTHOUGH NOT ANALYZED BY WPC...THERE ALSO APPEARS
TO BE TROUGH AXIS EXTENDING NE FROM THIS GULF LOW/WAVE ACROSS
CENTRAL FLORIDA AND INTO THE ATLC. WINDS HAVE TURNED LIGHT N/NE
BEHIND THIS TROUGH AXIS FROM ORLANDO NORTHWARD WHILE SE WINDS EXIST
TO THE SOUTH. NOT A SIGNIFICANT IMPACT EXCEPT TO BOATERS NORTH OF
THE CAPE SO UPDATED THE COASTAL MARINE FCST EARLIER. EXPECT A MORE
UNIFORM E/NE FLOW TO DEVELOP THIS AFTERNOON AS THE TROUGH AXIS
WEAKENS.
WEAK UPGLIDE WILL KEEP THE AREA MOSTLY CLOUDY TO CLOUDY WITH ON AND
OFF PATCHES OF LIGHT RAIN/SPRINKLES. THERE MAY BE SOME ADDITIONAL
BREAKS IN THE CLOUDS LATER IN THE DAY. HIGHS WILL REACH THE UPPER
70S ORLANDO NORTH AND LOWER 80S SOUTH.
&&
.AVIATION...
LARGE AREA OF IFR CIGS AND VSBYS EXIST ACROSS NORTH FL AND GA AND
HAVE BEEN CREEPING SOUTHWARD. BUT MID AND HIGH LEVEL OVERCAST ACROSS
OUR TERMINALS HAS KEPT THE LOW CLOUDS AT BAY. IT IS POSSIBLE SOME
LOW CLOUDS MAY REACH DAB/LEE THROUGH 16Z BUT WILL HANDLE WITH AMD IF
NECESSARY. OTHERWISE VFR WITH PREVAILING CIGS BKN-OVC100-150 AND LCL
BKN040-060 IN LIGHT PRECIP. COULD SEE SOME LOCAL MVFR VSBYS (NEAR
5SM) IN RAIN. THERE MAY BE A BETTE CHANCE FOR IFR/MVFR FOG/MIST AFT
08Z TONIGHT ACROSS THE NORTH (LEE-DAB).
&&
.MARINE...
TRICKY WIND FORECAST THIS MORNING AS A WEAK SURFACE TROUGH HAS
DROPPED INTO THE AREA. NORTH TO NORTHEAST WINDS UP TO 15 KNOTS JUST
NORTH OF THE CAPE AND SOUTH SOUTHEAST WINDS UP TO 15 KNOTS SOUTH OF
THE CAPE. THIS TROUGH APPEARS TO BE TRANSITING E/SE SO MUCH OF THE
BREVARD COASTAL WATERS MAY SEE A WIND SHIFT OUT OF THE N/NE THIS
MORNING. DO NOT THINK IT WILL MAKE IT SOUTH OF SEBASTIAN INLET. THE
TREND GOING INTO THE AFTN SHOULD BE FOR THIS TROUGH/BOUNDARY TO
DIMINISH AND ALLOW A MORE UNIFORM E/NE FLOW AROUND 10 KNOTS TO
DEVELOP ACROSS ALL THE WATERS. WILL MAINTAIN CAUTION HEADLINE FOR
THE OFFSHORE WATERS AND NEARSHORE TREASURE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 77 68 80 69 / 30 20 10 20
MCO 79 65 84 67 / 40 30 10 20
MLB 79 72 81 69 / 40 20 10 10
VRB 80 72 82 68 / 40 20 10 10
LEE 79 65 83 66 / 30 30 10 20
SFB 79 65 83 67 / 30 20 10 20
ORL 79 66 83 67 / 40 30 10 20
FPR 80 71 82 69 / 40 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
920 AM EST SAT NOV 16 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN
ONSHORE FLOW INTO THE FORECAST AREA THROUGH SUNDAY. AN APPROACHING
COLD FRONT WILL MOVE THROUGH THE AREA MONDAY. COLD HIGH PRESSURE
WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PATCHY FOG CONTINUES THIS MORNING MAINLY AROUND THE COLUMBIA METRO
AREA...NOT WIDESPREAD AND EXPECT SLOWLY IMPROVING VISIBILITY
DURING THE MORNING.
THE NAM AND GFS SHOW RISING H5 HEIGHTS TODAY. WEAK ISENTROPIC
LIFT SHOULD SUPPORT SOME CLOUDINESS BUT MOISTURE SHOULD REMAIN
SHALLOW. ALL OF THE MOS INDICATES POPS LESS THAN 20 PERCENT. WE
WILL GET OFF TO A RELATIVELY WARM START AND WITH RISING HEIGHTS
EXPECT TEMPERATURES WILL REACH THE UPPER 60S AND LOWER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE MODELS DISPLAY UPPER HEIGHTS BEGINNING TO FALL TONIGHT IN RESPONSE
TO A FAST MOVING TROUGH ACROSS THE UPPER MIDWEST AND DEEPENING
SURFACE LOW OVER THE GREAT LAKES. A COLD FRONT WILL PUSH EASTWARD
ACROSS THE OHIO AND TENNESSEE VALLEYS SUNDAY EVENING AND PUSH
THROUGH THE FORECAST AREA EARLY MONDAY. AHEAD OF THE FRONT...A
30- TO 40-KNOT H85 JET WILL PROVIDE ADEQUATE MOISTURE TRANSPORT
AS PRECIPITABLE WATER VALUES INCREASE TO NEAR 2 INCHES (OVER 2
STANDARD DEVIATIONS ABOVE NORMAL). WILL CONTINUE TO FORECAST AN
INCREASE IN POPS THROUGH THE AFTERNOON SUNDAY PEAKING WITH LIKELY
POPS SUNDAY NIGHT. THERE MAY BE ENOUGH INSTABILITY FOR
THUNDERSTORMS SUNDAY NIGHT. THE NAM INDICATES SURFACE-BASED LI/S
OF 0 TO -2. SHEAR WILL BE HIGH BUT THE SEVERE THREAT APPEARS
LIMITED BECAUSE OF A LACK OF SIGNIFICANT INSTABILITY. POPS SHOULD
RAPIDLY DECREASE MONDAY BEHIND THE FRONT. TEMPERATURES AHEAD OF
THE FRONT SUNDAY WILL AGAIN BE WARM AND WELL ABOVE NORMAL.
HIGH PRESSURE WILL BUILD INTO THE AREA WITH NORTHERLY WINDS IN THE
WAKE OF THE COLD FRONT OFF THE COAST AS THE UPPER FLOW BECOMES
WESTERLY. THE COOLER AIR WILL BE LAGGING WELL BEHIND THE FRONT AND
MONDAY WILL LIKELY FEATURE WELL ABOVE NORMAL TEMPERATURES IN THE
70S AFTER A VERY WARM SUNDAY NIGHT WHERE LOW TEMPERATURES ARE
EXPECTED TO BE 15 TO 20 DEGREES ABOVE NORMAL BECAUSE OF CLOUDINESS
AND MIXING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
WE HAVE REASONABLY HIGH CONFIDENCE IN A DRY AND FAIR WEATHER
PATTERN DURING THE MEDIUM-RANGE PERIOD WITH GOOD MODEL AGREEMENT.
THE UPPER PATTERN TUESDAY FEATURES A TROUGH PUSHING OFF THE MID-
ATLANTIC COAST WITH WEST TO NORTHWESTERLY FLOW OVER THE FORECAST
AREA. GENERALLY DRY ZONAL FLOW EXPECTED WEDNESDAY THROUGH FRIDAY.
SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION TUESDAY IN THE
WAKE OF THE FRONTAL PASSAGE MONDAY. COOL H85 TEMPERATURES WILL
SETTLE OVER THE FORECAST AREA THROUGH MIDWEEK AND DESPITE EXPECTED
SUNSHINE...EXPECT TEMPERATURES TO REMAIN SLIGHTLY BELOW NORMAL.
SHORTWAVE RIDGING DEVELOPS OVER THE SOUTHEAST BY FRIDAY IN
RESPONSE TO A SHARPLY DIGGING UPSTREAM TROUGH BUT PERSISTENT
NORTHEASTERLY SURFACE FLOW WILL CONTINUE TO LIMIT WARMING.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
LATEST HRRR GUIDANCE SUGGESTING LOW STRATUS AND OR FOG WILL
CONTINUE ACROSS THE AREA THROUGH LATE MORNING...
IFR/LIFR CONDITIONS EXPECTED TO CONTINUE ACROSS MUCH OF THE
FORECAST AREA UNTIL AROUND 15Z-16Z THIS MORNING THEN SLOW IMPROVEMENT.
BY 18Z EXPECT VFR ALL TAF SITES WITH A LIGHT EASTERLY WIND.
EXTENDED AVIATION OUTLOOK...INCREASING CONFIDENCE IN RESTRICTIONS
SUNDAY MORNING INTO MONDAY. A COLD FRONT IS FORECAST TO CROSS THE
AREA EARLY MONDAY. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
957 AM CST SAT NOV 16 2013
.DISCUSSION...
815 AM CST
FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING.
THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA.
ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES
HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON
THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE.
THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF
UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE
TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE
CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS
TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY
EARLY AFTERNOON AND SPREADING EAST FROM THERE.
MTF
//PREV DISCUSSION...
333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY.
IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA
SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE.
DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING
WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER
50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST
AHEAD OF THE COLD FRONT SUNDAY MORNING.
LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS
EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR
TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP
SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED
JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE
ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER
WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE
INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES.
THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING
WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT
EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE
SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY
RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A
LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS
WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE.
DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS
AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS
WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY
IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S
TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF
THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY
BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS
EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN
CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING.
A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND
QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY
DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES
LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE
ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID
SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE
EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW...
DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO
SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME...
ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD
FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS
OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO
WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS
UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING
SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY
ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG
STORMS CAN/T BE RULED OUT.
ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS
LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER
OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY
IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS
NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS
STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND
WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT
LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE
OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL
UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP...
JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST
INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS
MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE
I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN
CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE
MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE
ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO
ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A
TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE
THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER
VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION
WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE
LOCALIZED DEPENDING ON CONVECTIVE COVERAGE.
STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE
30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR
WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME
OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT
WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY...
LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS
WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/
COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES.
THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER
SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY.
HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH
TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY
SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS
IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C
TO +15C RANGE.
WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE
ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH
PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND
THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED.
WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S...
MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE
AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL
FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY
WARMER.
HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS
TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO
NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS
EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO
THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW
SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH
THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS
AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND
WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN
PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF
FRONT AND END TIME OF PRECIP. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* DRIZZLE AND IFR CONDITIONS THROUGH EARLY AFTERNOON...WITH EVEN
A CHANCE OF TEMPORARY LIFR.
* MVFR CIGS LIKELY WITH A CHANCE OF IFR CIGS TONIGHT.
* SOUTH WINDS INCREASING THROUGH THE MORNING WITH GUSTS 25-30 KT
THIS AFTERNOON. SOUTH TO SOUTHWEST WIND GUSTS IN EXCESS OF 30 KT
EXPECTED SUNDAY.
* SHRA EXPECTED LATE THIS AFTERNOON THROUGH THE EVENING WITH
THUNDER POSSIBLE. ADDITIONAL LOWER SHRA/TSRA CHANCES OVERNIGHT
WITH AN INCREASING CHANCE AFTER DAYBREAK SUNDAY.
* LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO
50 KT.
MTF/MDB
//DISCUSSION...UPDATED 14Z...
TAFS HAVE BEEN UPDATED TO INCLUDE MORE PESSIMISTIC CONDITIONS THIS
MORNING DUE TO DRIZZLE AND IFR VISIBLITIES. IFR CONDITIONS EXIST
WELL UPSTREAM ACROSS CENTRAL IL SO MAY NEED TO EXTEND DURATION
INTO THE AFTERNOON. THERE HAVE BEEN TEMPORARY LIFR CONDITIONS
OBSERVED AT SOME AIRPORTS AND POSSIBLE THIS IS SEEN AT SOME OF THE
TAF SITES THROUGH EARLY AFTERNOON.
PREV DISCUSSION...UPDATED 12Z...
LOW PRESSURE IS ORGANIZING ACROSS THE CENTRAL AND NORTHERN PLAINS
AND WILL MOVE NORTHEAST TO LAKE SUPERIOR TONIGHT. INCREASING
SOUTHERLY FLOW HAS BROUGHT AN INFLUX OF STRATUS AND SOME MIST TO
THE TERMINALS OVERNIGHT. SEVERAL SITES HAD DIPPED TO IFR BUT HAVE
BEEN SEEING IMPROVEMENT UPSTREAM OVER THE LAST HOUR OR TWO. EXPECT
THE IFR CIGS/VSBY TO IMPROVE WITH A STEADIER MVFR CLOUD DECK
BECOMING ESTABLISHED THROUGH THE MORNING...LIKELY IN THE 1000-2000
FT RANGE. MVFR LOOKS TO CONTINUE THROUGH THE NIGHT...THOUGH THERE
MAY BE SOME BREAKS AT TIMES LATER TODAY AND TONIGHT BUT CONFIDENCE
IN DETAILS IS LOW. WINDS WILL BE INCREASING THROUGH THE MORNING
WITH GUSTS BECOMING MORE FREQUENT INTO THE AFTERNOON AS GUSTS
SPEEDS PUSH 25 TO 30 KT. AN UPPER LEVEL TROUGH WILL CROSS THE AREA
LATE THIS AFTERNOON AND THIS EVENING BRINGING SHOWERS WITH IT AS
WELL AS AT LEAST A CHANCE FOR THUNDER. HAVE DECENT CONFIDENCE IN
THUNDER OCCURRING THOUGH TI MAY NIT IMPACT EACH TERMINAL DIRECTLY.
THERE LOOKS TO BE A LULL IN THE PRECIP LATER THIS EVENING AND
EARLY TONIGHT BEFORE CHANCE INCREASE EARLY SUNDAY MORNING AS
ANOTHER PUSH OF WARMER AIR STREAMS OVER. CIGS MAY LOWER TO IFR
OVERNIGHT BUT WILL JUST HINT AT IT WITH SCT IFR LEVEL CLOUD
MENTION FOR NOW. WIND GUSTS SHOULD CONTINUE THROUGH THE EVENING
AND MAY EVEN INCREASE. RAIN.THUNDER COVERAGE AND TIMING IS
SOMEWHAT UNCERTAIN GOING INTO SUNDAY MORNING BUT CHANCES WILL
LIKELY INCREASE UNTIL A COLD FRONT CROSSES THE AREA IN CONJUNCTION
WITH A SECOND AND MORE INTENSE LOW PRESSURE AREA MOVING NORTH OF
THE AREA. SOUTH TO SOUTHWEST WINDS WILL INCREASE SUNDAY MORNING
AND GUSTS IN EXCESS OF 35 KT A GOOD POSSIBILITY...WITH THE
DIRECTION TURNING MORE WESTERLY THROUGH THE DAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN IFR CONDITIONS LATE THIS MORNING WITH AT
LEAST TEMPORARY SUB 700 FT CIGS AND <3SM VISIBILITY. LOW
CONFIDENCE IN DURATION OF THESE CONDITIONS.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS CONTINUING THROUGH TONIGHT.
LOW CONFIDENCE IN IF THERE WILL BE ANY BREAKS TO VFR.
* HIGH CONFIDENCE IN WIND DIRECTION FORECAST AND SPEED
TRENDS...MEDIUM CONFIDENCE IN TIMING OF GUST DEVELOPMENT.
* HIGH CONFIDENCE IN SHRA ARRIVING LATER TODAY...MEDIUM-HIGH
CONFIDENCE IN TIMING. MEDIUM-HIGH CONFIDENCE THAT THERE WILL BE
AT LEAST SOME THUNDER IN THE AREA.
* MEDIUM CONFIDENCE IN LOW LEVEL WIND SHEAR SATURDAY EVENING BUT
SURFACE GUSTS MAY PRECLUDE IT.
MTF/MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE.
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN
AT NIGHT. MAINLY VFR.
MDB
&&
.MARINE...
354 AM CST
GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS
SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH
PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE
HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD
ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO
OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE
SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS
THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE
ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION
WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE
TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND
CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE
IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE
AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS
WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER
MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES.
WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY
SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL
HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A
STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL
RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF
MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN
NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO
SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER
LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE
DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR
MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS
THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP
COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING
LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45
KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY
EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE
WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO
THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP
AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY
ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE
WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO
HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES
THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND
NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A
CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE
EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY
WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN
EYE ON THIS.
OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE
PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN
EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE
MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH
WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL NOON SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 4
AM MONDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
819 AM CST SAT NOV 16 2013
.DISCUSSION...
815 AM CST
FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING.
THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA.
ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES
HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON
THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE.
THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF
UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE
TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE
CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS
TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY
EARLY AFTERNOON AND SPREADING EAST FROM THERE.
MTF
&&
.PREV DISCUSSION...
333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY.
IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA
SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE.
DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING
WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER
50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST
AHEAD OF THE COLD FRONT SUNDAY MORNING.
LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS
EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR
TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP
SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED
JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE
ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER
WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE
INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES.
THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING
WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT
EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE
SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY
RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A
LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS
WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE.
DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS
AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS
WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY
IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S
TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF
THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY
BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS
EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN
CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING.
A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND
QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY
DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES
LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE
ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID
SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE
EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW...
DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO
SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME...
ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD
FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS
OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO
WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS
UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING
SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY
ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG
STORMS CAN/T BE RULED OUT.
ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS
LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER
OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY
IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS
NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS
STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND
WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT
LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE
OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL
UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP...
JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST
INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS
MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE
I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN
CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE
MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE
ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO
ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A
TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE
THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER
VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION
WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE
LOCALIZED DEPENDING ON CONVECTIVE COVERAGE.
STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE
30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR
WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME
OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT
WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY...
LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS
WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/
COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES.
THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER
SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY.
HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH
TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY
SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS
IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C
TO +15C RANGE.
WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE
ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH
PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND
THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED.
WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S...
MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE
AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL
FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY
WARMER.
HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS
TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO
NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS
EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO
THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW
SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH
THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS
AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND
WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN
PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF
FRONT AND END TIME OF PRECIP. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* DRIZZLE AND IFR CONDITIONS THIS MORNING...WITH EVEN A CHANCE OF
TEMPORARY LIFR.
* MVFR CIGS LIKELY WITH A CHANCE OF IFR CIGS TONIGHT.
* SOUTH WINDS INCREASING THROUGH THE MORNING WITH GUSTS 25-30 KT
THIS AFTERNOON. SOUTH TO SOUTHWEST WIND GUSTS IN EXCESS OF 30 KT
EXPECTED SUNDAY.
* SHRA EXPECTED LATE THIS AFTERNOON THROUGH THE EVENING WITH
THUNDER POSSIBLE. ADDITIONAL LOWER SHRA/TSRA CHANCES OVERNIGHT
WITH AN INCREASING CHANCE AFTER DAYBREAK SUNDAY.
* LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO
50 KT.
MTF/MDB
//DISCUSSION...UPDATED 14Z...
TAFS HAVE BEEN UPDATED TO INCLUDE MORE PESSIMISTIC CONDITIONS THIS
MORNING DUE TO DRIZZLE AND IFR VISIBLITIES. IFR CONDITIONS EXIST
WELL UPSTREAM ACROSS CENTRAL IL SO MAY NEED TO EXTEND DURATION
INTO THE AFTERNOON. THERE HAVE BEEN TEMPORARY LIFR CONDITIONS
OBSERVED AT SOME AIRPORTS AND POSSIBLE THIS IS SEEN AT SOME OF THE
TAF SITES THROUGH EARLY AFTERNOON.
PREV DISCUSSION...UPDATED 12Z...
LOW PRESSURE IS ORGANIZING ACROSS THE CENTRAL AND NORTHERN PLAINS
AND WILL MOVE NORTHEAST TO LAKE SUPERIOR TONIGHT. INCREASING
SOUTHERLY FLOW HAS BROUGHT AN INFLUX OF STRATUS AND SOME MIST TO
THE TERMINALS OVERNIGHT. SEVERAL SITES HAD DIPPED TO IFR BUT HAVE
BEEN SEEING IMPROVEMENT UPSTREAM OVER THE LAST HOUR OR TWO. EXPECT
THE IFR CIGS/VSBY TO IMPROVE WITH A STEADIER MVFR CLOUD DECK
BECOMING ESTABLISHED THROUGH THE MORNING...LIKELY IN THE 1000-2000
FT RANGE. MVFR LOOKS TO CONTINUE THROUGH THE NIGHT...THOUGH THERE
MAY BE SOME BREAKS AT TIMES LATER TODAY AND TONIGHT BUT CONFIDENCE
IN DETAILS IS LOW. WINDS WILL BE INCREASING THROUGH THE MORNING
WITH GUSTS BECOMING MORE FREQUENT INTO THE AFTERNOON AS GUSTS
SPEEDS PUSH 25 TO 30 KT. AN UPPER LEVEL TROUGH WILL CROSS THE AREA
LATE THIS AFTERNOON AND THIS EVENING BRINGING SHOWERS WITH IT AS
WELL AS AT LEAST A CHANCE FOR THUNDER. HAVE DECENT CONFIDENCE IN
THUNDER OCCURRING THOUGH TI MAY NIT IMPACT EACH TERMINAL DIRECTLY.
THERE LOOKS TO BE A LULL IN THE PRECIP LATER THIS EVENING AND
EARLY TONIGHT BEFORE CHANCE INCREASE EARLY SUNDAY MORNING AS
ANOTHER PUSH OF WARMER AIR STREAMS OVER. CIGS MAY LOWER TO IFR
OVERNIGHT BUT WILL JUST HINT AT IT WITH SCT IFR LEVEL CLOUD
MENTION FOR NOW. WIND GUSTS SHOULD CONTINUE THROUGH THE EVENING
AND MAY EVEN INCREASE. RAIN.THUNDER COVERAGE AND TIMING IS
SOMEWHAT UNCERTAIN GOING INTO SUNDAY MORNING BUT CHANCES WILL
LIKELY INCREASE UNTIL A COLD FRONT CROSSES THE AREA IN CONJUNCTION
WITH A SECOND AND MORE INTENSE LOW PRESSURE AREA MOVING NORTH OF
THE AREA. SOUTH TO SOUTHWEST WINDS WILL INCREASE SUNDAY MORNING
AND GUSTS IN EXCESS OF 35 KT A GOOD POSSIBILITY...WITH THE
DIRECTION TURNING MORE WESTERLY THROUGH THE DAY.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN IFR CONDITIONS THIS MORNING WITH AT LEAST
TEMPORARY SUB 700 FT CIGS AND <3SM VISIBILITY. LOW CONFIDENCE IN
DURATION OF THESE CONDITIONS.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS CONTINUING THROUGH TONIGHT.
LOW CONFIDENCE IN IF THERE WILL BE ANY BREAKS TO VFR.
* HIGH CONFIDENCE IN WIND DIRECTION FORECAST AND SPEED
TRENDS...MEDIUM CONFIDENCE IN TIMING OF GUST DEVELOPMENT.
* HIGH CONFIDENCE IN SHRA ARRIVING LATER TODAY...MEDIUM-HIGH
CONFIDENCE IN TIMING. MEDIUM-HIGH CONFIDENCE THAT THERE WILL BE
AT LEAST SOME THUNDER IN THE AREA.
* MEDIUM CONFIDENCE IN LOW LEVEL WIND SHEAR SATURDAY EVENING BUT
SURFACE GUSTS MAY PRECLUDE IT.
MTF/MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE.
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN
AT NIGHT. MAINLY VFR.
MDB
&&
.MARINE...
354 AM CST
GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS
SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH
PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE
HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD
ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO
OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE
SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS
THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE
ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION
WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE
TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND
CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE
IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE
AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS
WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER
MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES.
WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY
SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL
HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A
STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL
RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF
MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN
NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO
SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER
LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE
DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR
MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS
THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP
COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING
LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45
KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY
EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE
WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO
THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP
AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY
ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE
WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO
HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES
THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND
NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A
CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE
EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY
WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN
EYE ON THIS.
OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE
PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN
EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE
MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH
WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL NOON SATURDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...NOON
SATURDAY TO 4 AM MONDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON SATURDAY TO 3 PM
MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST SAT NOV 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE
UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST
THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR
PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND.
FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A
SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE
NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND
EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO
SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER
LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE
HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER
THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN
UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED
AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL
BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION
TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS
IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING
AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN.
THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE
ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH
THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO
BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD
MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY
THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH
FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE
CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY
AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE
FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL
CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST
HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE
A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT
VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE
EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED
THUNDERSTORMS.
AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND
SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA
LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z
SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR
TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH
POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST
FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS
REASONABLE) AND ONLY MADE MINOR TWEAKS.
ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY
AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING
TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP
MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO
DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP
WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS).
DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS
EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A
STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE
HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY
WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS
LOWER LEVEL AIR SLIDES IN.
FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND
TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER
THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE
INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT
WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE
20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL
TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES
NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN
TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING
AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 521 AM EST SAT NOV 16 2013
LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE
UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG
WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A
TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT
MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A
SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK
RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN
INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS
AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER
WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY
PROBABLY LIGHT LES OFF LAKE SUPERIOR.
BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT
ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY
DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB
HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO
THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES
DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH
WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH
A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND.
IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND
E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE
CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE
SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW.
INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT
OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA
OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN
PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE
LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST.
WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A
MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA...
GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING
IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W
TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL
FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY
DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS.
BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD
DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST
SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL
SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T
APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL
IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL
PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN
LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY.
AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER
THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS
SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE
PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO
AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT
LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT
SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE
MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION
ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO
GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO
SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY
THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL.
LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW
ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO
SNOW ARE WARRANTED AT THIS TIME.
WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE
DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB
DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL
TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT
ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL
ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE
WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED
FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR...
HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT
POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT
INTO MON MORNING.
TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS
850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END
OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS
AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE
REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS
CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE
GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT
THESE COLDER NUMBERS.
WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG
SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT
ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET
UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE
INTENSITY OF THE COLD FOLLOWING THE FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 644 AM EST SAT NOV 16 2013
SOUTHERLY WINDS WILL INCREASE LOW LEVEL MOISTURE ACROSS UPPER
MICHIGAN TODAY AHEAD OF A DISTURBANCE MOVING THROUGH THIS EVENING.
THIS INCREASING LOW LEVEL MOISTURE WILL PRODUCE A QUICK TRANSITION
FROM VFR CONDITIONS TO IFR CEILINGS THIS AFTERNOON. THEN THE
APPROACHING DISTURBANCE WILL BRING A WIDE SWATH OF RAIN THIS
EVENING AND LEAD TO LOWER CEILINGS AND VISIBILITIES...ESPECIALLY AT
KSAW WHERE THEY WILL BE BORDERLINE AIRFIELD LANDING MINS. MODELS ARE
SHOWING DRIER AIR ARRIVING OVER THE WEST AFTER MIDNIGHT AND HAVE
TRENDED CEILINGS UP AS THE RAIN ENDS. KSAW WILL HAVE THE LOW
CEILINGS REMAINING THROUGH MUCH OF THE NIGHT BUT EXPECT CONDITIONS
TO TRY TO IMPROVE BY DAYBREAK.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW
MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY.
STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE
SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE
LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF
LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH
FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT
WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS
WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES
ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL
BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON
MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES...
GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END
GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E
HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE
E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E
MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN
RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT
APPROACHING LOW PRES TROF.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ248>251-265>267.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ241>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EST SAT NOV 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE
UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST
THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR
PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND.
FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A
SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE
NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND
EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO
SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER
LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE
HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER
THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN
UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED
AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL
BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION
TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS
IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING
AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN.
THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE
ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH
THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO
BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD
MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY
THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH
FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE
CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY
AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE
FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL
CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST
HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE
A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT
VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE
EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED
THUNDERSTORMS.
AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND
SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA
LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z
SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR
TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH
POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST
FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS
REASONABLE) AND ONLY MADE MINOR TWEAKS.
ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY
AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING
TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP
MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO
DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP
WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS).
DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS
EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A
STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE
HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY
WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS
LOWER LEVEL AIR SLIDES IN.
FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND
TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER
THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE
INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT
WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE
20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL
TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES
NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN
TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING
AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 521 AM EST SAT NOV 16 2013
LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE
UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG
WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A
TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT
MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A
SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK
RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN
INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS
AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER
WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY
PROBABLY LIGHT LES OFF LAKE SUPERIOR.
BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT
ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY
DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB
HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO
THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES
DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH
WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH
A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND.
IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND
E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE
CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE
SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW.
INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT
OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA
OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN
PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE
LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST.
WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A
MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA...
GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING
IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W
TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL
FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY
DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS.
BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD
DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST
SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL
SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T
APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL
IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL
PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN
LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY.
AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER
THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS
SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE
PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO
AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT
LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT
SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE
MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION
ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO
GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO
SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY
THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL.
LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW
ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO
SNOW ARE WARRANTED AT THIS TIME.
WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE
DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB
DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL
TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT
ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL
ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE
WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED
FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR...
HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT
POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT
INTO MON MORNING.
TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS
850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END
OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS
AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE
REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS
CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE
GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT
THESE COLDER NUMBERS.
WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG
SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT
ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET
UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE
INTENSITY OF THE COLD FOLLOWING THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1223 AM EST SAT NOV 16 2013
EXPECT VFR CONDITIONS OVERNIGHT BEFORE THE ARRIVAL OF GREATER LOW
LEVEL MOISTURE WITH INCREASING SRLY FLOW BRINGS MVFR CIGS INTO THE
AREA SATURDAY MORNING. LLWS WAS MENTIONED AT ALL TAF SITES WITH 40
KNOT WINDS EXPECTED ABOVE A STRENGTHENING INVERSION. THE ONSET OF
IFR CIGS IS EXPETED EARLIEST AT SAW WITH UPSLOPE SRLY FLOW. BY LATE
AFTERNOON AS RAIN ARRIVES INTO THE AREA...CONDITIONS SHOULD ALSO
DROP TO IFR AT CMX/IWD. ALTHOUGH FOG WILL ALSO DEVELOP...RAIN SHOULD
HELP KEEP THE VSBY FROM FALLING BLO 1-2SM SATURDAY EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW
MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY.
STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE
SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE
LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF
LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH
FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT
WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS
WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES
ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL
BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON
MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES...
GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END
GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E
HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE
E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E
MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN
RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT
APPROACHING LOW PRES TROF.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ248>251-265>267.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ241>245-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EST SAT NOV 16 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL EXTEND ACROSS CENTRAL NC TODAY THEN DRIFT
EAST TONIGHT AND SUNDAY. A STRONG COLD FRONT WILL APPROACH FROM THE
WEST SUNDAY AND CROSS OUR AREA SUNDAY NIGHT THROUGH EARLY MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM SATURDAY...
REST OF TODAY: AS THE PREVIOUS SHIFT NOTED... THE BIGGEST CHALLENGE
TODAY IS THE EXTENT OF CLOUD COVER AND ITS EFFECTS ON TEMPS. THE 12Z
GSO SOUNDING SHOWED DEEP NEAR-SATURATION EXTENDING UP TO 650 MB...
AND AREA PILOT REPORTS THIS MORNING INDICATE CLOUD DEPTHS UP TO 3K
FT. TRIAD FORECAST SOUNDINGS FROM RECENT RAP MODEL RUNS DID NOT
DEPICT THE CLOUD DEPTH WELL (LITTLE TOO DRY ABOVE 850 MB)...
ALTHOUGH THE UPSTREAM 12Z FFC SOUNDING DOES SUGGEST WE`LL SEE SOME
DRYING ALOFT (ABOVE 900 MB) THROUGH THE DAY. THE VERY LIGHT
NEAR-SURFACE WINDS ALONG WITH THE STABILITY OF THE LOWEST 50-100 MB
WILL LIMIT VERTICAL AND HORIZONTAL MIXING HOWEVER WITH THIS AIR MASS
BANKED UP AGAINST THE HIGHER TERRAIN... AND EXPECT THAT THESE CLOUDS
WILL HOLD FIRM FOR MUCH OF THE DAY ACROSS OUR WRN CWA. THE LIGHTER
WINDS IN THE ERN CWA WILL DISCOURAGE MIXING EVEN MORE... AND A
RECENT AMDAR AIRCRAFT SOUNDING FROM RDU SHOWS THE MOIST LAYER
STRETCHING UP TO 750 MB... SO THE FEW BREAKS AND THIN SPOTS
CURRENTLY OVER THE CENTRAL/ERN PIEDMONT MAY BE THE PEAK OF SUNSHINE
UNTIL LATER THIS AFTERNOON (AFTER 3 PM). ALL OF THIS SHOULD PUT A
DAMPER ON TEMPS... AND BASED ON THE LATEST READINGS... WE MAY ONLY
SEE READINGS CLIMB ANOTHER 10 OR SO DEGREES THROUGH THE DAY. WILL
NUDGE HIGHS SLIGHT DOWNWARD IN THE WEST AND UPWARD IN THE EAST AND
SOUTH (WHICH IS SEEING THE MOST SUNSHINE THIS MORNING). HIGHS 62 NW
TO 72 EAST. -GIH
TONIGHT...LIGHT/NEAR CALM WIND REGIME AND PLENTY OF MOISTURE IN THE
LOWEST 5K-8K FT SUGGEST A RETURN OF LOW OVERCAST WITH THE POTENTIAL
FOR AREAS OF FOG. COULD SEE SOME DRIZZLE THEN ISENTROPIC LIFT
MARGINAL AT BEST. THE MODIFYING AIR MASS AND EXTENSIVE CLOUD COVER
WILL MAINTAIN RELATIVELY MILD OVERNIGHT TEMPS FOR THIS TIME OF YEAR.
MIN TEMPS GENERALLY IN THE LOWER 50S. -WSS
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 315 AM SATURDAY...
SUNDAY...S/W RIDGE EXITS OUR REGION EARLY SUNDAY. THIS WILL ALLOW A
S/W IN THE NORTHERN STREAM TO PROGRESS E-NE FROM THE
CENTRAL-NORTHERN PLAINS INTO THE WESTERN LAKES BY EARLY SUNDAY
EVENING. THE SFC COLD FRONT ATTENDANT WITH THE S/W SHOULD STRETCH
FROM LAKE MICHIGAN SSW TO NEAR MEMPHIS. THE APPROACH OF THIS FRONTAL
SYSTEM WILL INDUCE AND STRENGTHEN A SLY FLOW ACROSS CENTRAL NC BY
SUNDAY AFTERNOON. WHILE CLOUDINESS WILL BE QUITE EXTENSIVE...THE
WARM SLY FLOW SHOULD BOOST TEMPS INTO THE 70-75 DEGREE RANGE. IF A
FEW RENEGADE SHOWERS WERE TO OCCUR SUNDAY AFTERNOON ACROSS THE
WEST...THESE SHOWERS MAY KNOCK TEMPS DOWN A FEW DEGREES. OTHERWISE
RAIN CHANCES THROUGH SUNSET APPEAR MINIMAL.
SUNDAY NIGHT...ATMOSPHERE WILL BE CHARACTERIZED AS A HIGH SHEAR/LOW
CAPE ENVIRONMENT AS A STRENGTHENING LOW LEVEL JET WILL CROSS OUR
REGION OVERNIGHT. THIS WILL RESULT IN BULK SHEAR VALUES INT HE
35-50KT RANGE...SUPPORTIVE OF ORGANIZED CONVECTION. CURRENTLY MODEL
INSTABILITY LACKING WITH MUCAPE VALUES NO WORSE THAN 250-300 J/KG
EXPECTED. REVIEW OF GFS BUFKIT SOUNDING DEPICT A RATHER EXTENSIVE
WARM LAYER IN THE 850-700MB LAYER. MID LEVEL LAPSE RATES APPEAR TO
BE NO WORSE THAN 5.5 DEG C/KM. DO WONDER IF MODEL INSTABILITY MAY BE
UNDERDONE AS SFC DEWPOINTS HAVE THE POTENTIAL TO RECOVER INTO THE
LOW-MID 60S OVER MOST OF CENTRAL NC. THUS CANNOT TOTALLY RULE OUT
THE POSSIBILITY OF A STRONG OR SEVERE STORMS OVERNIGHT SUNDAY NIGHT.
HOWEVER...SUCH OCCURRENCE APPEARS TO BE VERY LIMITED AT THIS TIME SO
REFRAIN FROM MENTIONING THUNDER AT THIS TIME AND AWAIT LATER MODEL
GUIDANCE/UPDATES. APPEARS TO BE FAIRLY DEEP LIFT WITH THE FRONT AND
MOISTURE PLENTIFUL. HAVE INCREASES POPS TO LIKELY OR LOW END
CATEGORICAL ACROSS THE REGION SUNDAY AS TH SFC FRONT SHOULD BE ON
OUR WESTERN PERIPHERY PRIOR TO DAYBREAK MONDAY. VERY MILD SUNDAY
NIGHT WITH MIN TEMPS NEAR 60 NW TO LOW-MID 60S ELSEWHERE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 315 AM SATURDAY...
MONDAY AND MONDAY NIGHT:
THE SURFACE COLD FRONT MENTIONED IN THE SHORT TERM IS EXPECTED TO
CROSS CENTRAL NC MONDAY MORNING INTO THE EARLY AFTERNOON... WITH THE
BEST CHANCE FOR SHOWERS... AND PERHAPS EVEN A FEW STORMS... IN
ADVANCE OF THE FRONT. FOR NOW... WILL SHOW THE HIGHEST POPS ACROSS
EASTERN AND SOUTHEASTERN PORTIONS OF THE AREA FOR THE MORNING
(SLIGHT CHANCE NW TO LIKELY E/SE)... WITH ONLY A LINGERING CHANCE IN
OUR FAR EAST/SOUTHEAST BY AFTERNOON. THE MAIN DYNAMICS ARE EXPECTED
TO PASS WELL TO THE NORTH OF THE AREA. GIVEN THIS AND THE TIME OF
DAY (MORNING) ALONG WITH THE GOOD LOW LEVEL JET PROGGED TO BE TO THE
EAST OF CENTRAL NC BY 12Z MONDAY... WE DO NOT ANTICIPATE ANY SEVERE
WEATHER. THE GOOD PUSH OF COLD AIR IS EXPECTED TO LAG THE FRONT
THOUGH... WITH DOWNSLOPE FLOW ON MONDAY. GIVEN THE DOWNSLOPE FLOW
AND QUICKLY CLEARING SKIES BEHIND THE FRONT... ALONG WITH TEMPS
STARTING OUT GENERALLY IN THE 60S ACROSS THE AREA... EXPECT HIGH
TEMPS WILL BE AROUND 70 NORTHWEST TO THE MID 70S... MAYBE EVEN UPPER
70S... SOUTHEAST.
HIGH PRESSURE WILL BUILD INTO THE AREA ON MONDAY NIGHT WITH LOW
TEMPS DRIVEN BY CAA. LOWS ON TUESDAY MORNING ARE EXPECTED TO RANGE
FROM THE UPPER 30S NORTH TO LOWER 40S SOUTH... WITH A NORTHWESTERLY
TO NORTHERLY WIND.
TUESDAY THROUGH FRIDAY:
SURFACE HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY/GREAT LAKES
REGION START THE PERIOD IS EXPECTED TO MOVE EASTWARD AND OFF THE
NORTHEAST/NEW ENGLAND COAST BY THURSDAY... WHILE EXTENDING SOUTHWARD
INTO CENTRAL NC. A LOW AMPLITUDE FLOW ALOFT WILL PERSIST ACROSS THE
REGION GENERALLY THROUGH THE REMAINDER OF THE FORECAST PERIOD...
ALTHOUGH HEIGHTS ALOFT WILL SLOWLY RISE THROUGH THIS TIMEFRAME.
MEDIUM RANGE MODELS ARE STRUGGLING HOW TO HANDEL THE EVOLUTION OF
THE LARGE SCALE FLOW PATTERN THOUGH... AT THE END OF THE FORECAST
PERIOD. NEAR THE END OF THE PERIOD MEDIUM RANGE MODELS BEGIN TO
TREND TO AN ERN PAC/WEST COAST RIDGE AND DOWNSTREAM TROUGHING
PATTERN. FOR NOW IT APPEARS THAT ANY SYSTEM ASSOCIATED WITH THIS
NEXT APPROACHING TROUGH WILL HOLD OFF UNTIL BEYOND THE MEDIUM RANGE.
THUS... FOR US WE SHOULD SEE DRY CONDITIONS FOR THE REMAINDER OF THE
WEEK WITH SLOWLY MODERATING TEMPS. HOWEVER... SKIES WILL BE SUNNY TO
START THE PERIOD... THEN TRANSITION TO PARTLY TO MOSTLY CLOUDY WITH
BOTH INCREASING HIGH LEVEL MOISTURE LATE WEEK FROM THE WEST ALONG
WITH EASTERLY FLOW ADVECTING IN MOISTURE OFF THE ATLANTIC ON
THURSDAY INTO FRIDAY AS THE SURFACE HIGH SHIFTS OFFSHORE. HIGH TEMPS
GENERALLY BE IN THE 50S... WITH LOWS RANGING FROM GENERALLY 30 TO 40
DEGREES... COLDEST ON WEDNESDAY MORNING (WHERE A FEW UPPER 20S CANT
BE RULED OUT).
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 645 AM SATURDAY...
WIDESPREAD LOW END MVFR/IFR CEILINGS ACROSS CENTRAL NC WITH POCKETS
OF MVFR VISIBILITY DUE TO FOG WILL PERSIST ACROSS CENTRAL NC UNTIL
14Z. AFTER WHICH...VISIBILITIES WILL IMPROVE TO GREATER THAN 6 MILES
AND CEILINGS WILL GRADUALLY LIFT THOUGH REMAIN IN THE MVFR RANGE
UNTIL 18Z-20Z. BY MID AFTERNOON...EXPECT CEILINGS TO CONTINUE TO
LIFT AND EVENTUALLY SCATTER AT MOST SPOTS WITH CLOUD BASES
3000-4000FT.
THE LOWER LAYERS OF THE ATMOSPHERE WILL REMAIN MOIST LATE TODAY
THROUGH TONIGHT. WITH LITTLE MIXING ANTICIPATED...EXPECT CEILINGS TO
LOWER SHORTLY AFTER SUNSET WITH WIDESPREAD LOW END MVFR/IFR
CEILINGS ANTICIPATED THIS EVENING AND PERSISTING INTO SUNDAY
MORNING. AGAIN...EXPECT A GRADUAL IMPROVEMENT IN CEILINGS LATE
SUNDAY MORNING INTO SUNDAY AFTERNOON. AN APPROACHING COLD FRONT WILL
INCREASE THE THREAT FOR SHOWERS AND ASSOCIATED MVFR
VISIBILITIES...ESPECIALLY SUNDAY NIGHT THROUGH EARLY MONDAY.
SOUTHERLY SFC WINDS WILL BECOME BREEZY AHEAD OF THE FRONT LATE
SUNDAY INTO SUNDAY NIGHT WITH SUSTAINED WINDS 10-15KTS AND GUST
20-25KTS PROBABLE SUNDAY NIGHT.
THE COLD FRONT WILL SWEEP THROUGH CENTRAL NC MONDAY MORNING. BEHIND
THE FRONT...MUCH DRIER AIR WILL QUICKLY DIMINISH THE SHOWERS AND
DISSIPATE THE CLOUD COVERAGE. VFR CONDITIONS SHOULD COVER CENTRAL NC
MONDAY AFTERNOON AND PERSIST THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
947 AM CST SAT NOV 16 2013
.UPDATE...
ISSUED AT 947 AM CST SAT NOV 16 2013
RADAR RETURNS CONTINUE OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA
AND HAVE EXPANDED AREAL COVERAGE OF SLIGHT CHANCE POPS. ALSO ADDED
A SLIGHT CHANCE OF PRECIPITATION OVER THE FAR SOUTHEAST COUNTIES
AS RETURNS HAVE INCREASED HERE AS WELL OVER THE PAST FEW HOURS.
PRECIPITATION WILL BE RAIN IN THE SOUTHEAST WITH A RAIN SNOW MIX
NORTH AND WEST FOR ANOTHER HOUR OR TWO...BEFORE RAIN THIS
AFTERNOON. PRECIPITATION AMOUNTS TODAY WILL BE LIGHT. A FEW AREAS
OF SUN OVER THE FAR SOUTH CENTRAL YET THIS MORNING...BUT CLOUDS
WILL CONTINUE TO INCREASE DURING THE DAY. WILL TAKE A CLOSER LOOK
AT TEMPERATURES LATE MORNING/EARLY THIS AFTERNOON.
UPDATE ISSUED AT 629 AM CST SAT NOV 16 2013
EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST
AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS
THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY
VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE
IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE
LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW
FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE
SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE
COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS
KEPT POPS LOW.
UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE
THE FORECAST LOOKS TO BE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST SAT NOV 16 2013
A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT
LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS
OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH
SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN
ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT
THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND
MUCH COLDER.
TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE
NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS
HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER
NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND
POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN
CHANGING TO SNOW.
FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE
/ SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM
THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY
ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL
MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST
AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH
TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN
ISOLATED RAIN SHOWER TO THE WEST.
FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND
SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON
THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO.
PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE
ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND
9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW
THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 310 AM CST SAT NOV 16 2013
SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED
STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN
PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT
REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR
SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS
APPROACHING CATEGORICAL IN THE NORTHWEST.
IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS
COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD
GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID
20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED
FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A
GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY.
SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY
ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO
SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST
EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A
POP AT THE MOMENT.
H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN
PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE
FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS
WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER
CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE
MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION
MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY.
WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 947 AM CST SAT NOV 16 2013
VFR WEATHER WILL PREVAIL THROUGH THE DAYLIGHT HOURS OF SATURDAY.
HIGH AND MID LEVEL CLOUDS WILL INCREASE FROM THE NORTHWEST THROUGH
THE DAY...AND LOWER AS MOISTURE INCREASES AFTER 16/18Z. A FEW SNOW
FLURRIES ARE POSSIBLE FOR THE AREA AROUND KISN THIS MORNING...THEN
ISOLATED RAIN SHOWERS SPREADING THROUGH KISN-KMOT-KDIK AFTER
16/22Z. SURFACE WINDS SATURDAY WILL BE 10 KNOTS OR LESS. THE RAIN
SHOWERS WILL CHANGE TO SNOW AS LOW PRESSURE APPROACHES AFTER
17/03Z...WITH MVFR CIGS ALSO POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JPM
LONG TERM...CK
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
643 AM CST SAT NOV 16 2013
.UPDATE...
ISSUED AT 629 AM CST SAT NOV 16 2013
EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST
AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS
THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY
VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE
IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE
LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW
FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE
SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE
COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS
KEPT POPS LOW.
UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE
THE FORECAST LOOKS TO BE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST SAT NOV 16 2013
A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT
LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS
OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH
SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN
ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT
THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND
MUCH COLDER.
TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE
NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS
HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER
NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND
POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN
CHANGING TO SNOW.
FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE
/ SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM
THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY
ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL
MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST
AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH
TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN
ISOLATED RAIN SHOWER TO THE WEST.
FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND
SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON
THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO.
PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE
ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND
9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW
THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 310 AM CST SAT NOV 16 2013
SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED
STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN
PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT
REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR
SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS
APPROACHING CATEGORICAL IN THE NORTHWEST.
IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS
COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD
GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID
20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED
FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A
GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY.
SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY
ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO
SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST
EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A
POP AT THE MOMENT.
H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN
PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE
FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS
WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER
CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE
MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION
MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY.
WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 642 AM CST SAT NOV 16 2013
BRIEF PATCHY FOG IS POSSIBLE AT KJMS EARLY THIS
MORNING...OTHERWISE VFR WEATHER WILL PREVAIL THROUGH THE DAYLIGHT
HOURS OF SATURDAY. HIGH AND MID LEVEL CLOUDS WILL INCREASE FROM
THE NORTHWEST THROUGH THE DAY...AND LOWER AS MOISTURE INCREASES
AFTER 16/18Z. A FEW SNOW FLURRIES ARE POSSIBLE FOR THE AREA
AROUND KISN THIS MORNING...THEN ISOLATED RAIN SHOWERS SPREADING
THROUGH KISN-KMOT-KDIK AFTER 16/22Z. SURFACE WINDS SATURDAY WILL
BE 10 KNOTS OR LESS. THE RAIN SHOWERS WILL CHANGE TO SNOW AS LOW
PRESSURE APPROACHES AFTER 17/03Z...WITH MVFR CIGS ALSO POSSIBLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...JPM
LONG TERM...CK
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
954 AM EST SAT NOV 16 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE REGION SUNDAY
NIGHT INTO EARLY MONDAY...FOLLOWED BY STRONG HIGH PRESSURE BUILDING
OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF MID MORNING...THE FCST APPEARS TO BE ON TRACK. SATELLITE
IMAGERY SHOWS THE HIGH ELEVATIONS OF THE NC MTNS ALREADY POKING UP
ABOVE THE LOW CLOUDS. A FEW HOLES IN THE OVERCAST ARE STARTING TO
OPEN UP OVER THE PIEDMONT OF THE CAROLINAS...BUT THESE MIGHT FILL
BACK IN WITH CLOUDS AT LEAST TEMPORARILY. THINK IT WILL TAKE A FEW
MORE HOURS...UNTIL MIDDAY...BEFORE WHOLESALE SCATTERING OCCURS.
TEMPS ARE IN GOOD SHAPE.
PREVIOUS DISCUSSION...
AS OF 245 AM EST SATURDAY...WIDESPREAD LOW CLOUDS AND AREAS OF FOG
WILL GRADUALLY LIFT AND PARTIALLY BURN OFF THIS MORNING. SO FAR THE
FOG HAS BEEN WELL SHORT OF ADVISORY CRITERIA. WITH ALL SITES
REPORTING A CEILING AT THIS HOUR...IT WOULD APPEAR THAT ANY DENSE
FOG THROUGH MID MORNING WILL BE ISOLATED. SCATTERED PATCHES OF RAIN
CONTINUE ATTM OVER WRN NC...BUT A WEAKENING LOW LEVEL WIND FIELD AND
NVA ALOFT SHOULD BRING THAT TO AN END IN A COUPLE HOURS. OTHERWISE
IT WILL BE A QUIET WEATHER DAY AS HEIGHTS RISE OVER THE REGION AHEAD
OF STRONG TROUGH DIGGING INTO THE CENTRAL HIGH PLAINS STATES.
LOW LEVEL WINDS WILL INCREASE IN SPEED TONIGHT AHEAD OF THAT
DEEPENING TROUGH. THE NAM H8 WINDS INCREASE TO AROUND 30 KTS. THE
STRENGTHENING WINDS AND INCREASING LLVL WARM ADVECTION AS A THERMAL
RIDGE MOVES IN FROM THE WEST WILL BE SUFFICIENT FOR ANOTHER ROUND OF
UPSLOPE ENHANCED LIGHT RAIN AND DRIZZLE. THE BULK OF THE PCPN SHOULD
BE CONFINED TO THE MOUNTAINS AND WRN FOOTHILLS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AT 230 AM EST SATURDAY...AN UPPER RIDGE WILL BE OFF THE EAST COAST
ON SATURDAY...WHILE AN UPPER TROUGH WILL BE OVER THE CENTER OF THE
NATION. THE DEAMPLIFYING TROUGH AXIS WILL PROGRESS TO THE CENTRAL
AND SOUTHERN APPALACHIANS BY BY MONDAY...MOVING OFF THE EAST COAST
ON MONDAY NIGHT.
SURFACE HIGH PRESSURE WIL WEAKEN ALONG THE EAST COAST ON SUNDAY...
WHILE A COLD FRONT CROSSES THE MS RIVER VALLEY. MOIST ISENTROPIC
UPGLIDE FLOW WILL PRECEDE THE FRONT ON SUNDAY AND SUNDAY NIGHT...
HOWEVER LOW LEVEL UPSLOPE FLOW WILL WEAKEN AS WINDS VEER AND BECOME
PARALLEL TO THE BLUE RIDGE. FRONTAL PASSAGE OVER OUR AREA IS
EXPECTED TO OCCUR LATE SUNDAY NIGHT AND EARLY MONDAY. WHILE BOTH THE
NAM AND GFS SHOW SHEAR CROSSING THE AREA WITH THE FRONT...NAM CAPE
IS MARGINAL...AND GFS CAPE MUCH WEAKER. THE SITUATION WILL NEED TO
BE MONITORED FOR THE POSSIBILITY OF A LOW CAPE...HIGH SHEAR
ENVIRONMENT. PRECIPITATION IS NOT EXPECTED TO BE EXCESSIVE...WITH
PERHAPS A BIT MORE THAN ONE INCH OF RAINFALL ALONG THE SOUTH FACING
BLUE RIDGE ESCARPMENT.
TEMPERATURES WILL WARM ABOVE NORMAL AHEAD OF THE FRONT...WITH A
REDUCED DIURNAL RANGE IN CLOUDS AND PRECIPITATION. TEMPERATURES WILL
WARM EVEN FURTHER ABOVE NORMAL MONDAY IN DOWNSLOPE FLOW BEHIND THE
FRONT....BUT WILL FALL BELOW NORMAL MONDAY NIGHT IN COLD ADVECTION
WITH WINDS DIMINISHING AND VEERING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 155 AM EST SATURDAY...TUESDAY THROUGH FRIDAY NIGHT...MEDIUM
RANGE MODELS SHOW HIGH PRESSURE CENTERED OVER ILLINOIS AT 12Z
TUESDAY WITH PRESSURE GRADIENT EASING OVER THE CAROLINAS. BY 00Z WED
THE CENTER OF THE HIGH IS OVER THE EASTERN GREAT LAKES WITH LOW
LEVEL WIND FLOW FOR OUR AREA BEING GENERALLY NE. AS THIS HIGH MOVES
OFF THE NEW ENGLAND COAST THURSDAY AFTERNOON...THE WIND FLOW BECOMES
MORE EAST TO SE AND TEMPS RISE A BIT FROM JANUARY TYPE TEMPS TO JUST
A FEW DEGREES BELOW NORMAL ON FRIDAY. THE GFS HAS A SURFACE LOW
FORMING OVER EAST TEXAS FRIDAY NIGHT AND MOVING NE WHILE THE ECMWF
HAS A LESS VIGOROUS TROUGH AND SURFACE DEVELOPMENT. BOTH OF THESE
MODELS HAVE AT LEAST SOME LIGHT PRECIP MOVING INTO THE WESTERN NC
MTNS BY LATE FRIDAY NIGHT. THEREFORE...I HAVE INTRODUCED SLIGHT POPS
FOR THAT AREA IN THE EXTRA PERIOD OF FRIDAY NIGHT.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...SKIES HAVE ACTUALLY CLEARED ABOUT 20 MILES TO THE
SOUTHEAST OF THE AIRFIELD. HOWEVER...THE LLVL FLOW IS WEAKLY OUT OF
THE SOUTHWEST AND CIGS BETWEEN 005-007 SHOULD LAST THROUGH ABOUT 15
UTC. THE NAM MODEL SOUNDINGS IMPLY CONDITIONS COULD IMPROVE
EARLIER...THE RAP LATER. WITH THE VERY LIGHT LLVL WINDS AND FAIRLY
WEAK INVERSION...I DON/T SEE THE IFR LEVEL CIGS HANGING AROUND MUCH
BEYOND 15 UTC...BUT I/M NOT TERRIBLY CONFIDENT ABOUT THIS. A PERIOD
OF VFR CONDITIONS IS EXPECTED TO DEVELOP THIS AFTERNOON...WITH
STRATUS RETURNING AGAIN TONIGHT. IN FACT...WITH A STRONGER WIND
FIELD AND BETTER WARM ADVECTION...I THINK THE CHANCES OF AN IFR DECK
ARE PRETTY GOOD.
ELSEWHERE...IFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING.
EXPECTING CIGS TO HOLD GENERALLY BETWEEN 007-010 OVER THE NEXT FEW
HOURS. HOWEVER...THERE HAVE BEEN BREAKS IN THE IFR WITH AN MVFR DECK
ABOVE THAT. ADDED A TEMPO GROUP TO ACCOUNT FOR THIS AT ALL SITES
EXCEPT KAVL. VSBYS SHOULD GENERALLY BE IN THE MVFR RANGE AT THE
UPSTATE SITES...AND A LITTLE LOWER IN NC. IT IS POSSIBLE THAT
CONDITIONS WILL WORSEN AFTER SUNRISE WITH THE MOIST LOW LEVELS. THE
LLVL WINDS LOOK TOO WEAK TO SUPPORT STRATUS...CAUSING ME TO BE
CONCERNED ABOUT INCREASING AMOUNTS OF FOG AFTER 12 UTC. I DON/T SEE
ANYTHING TO REALLY HANG MY HAT ON IN THIS REGARD...WHICH IS WHY THE
TAFS SIMPLY REFLECT THE PREVAILING CONDITIONS FOR ANOTHER 3 HOURS OR
SO. THERE SHOULD BE SOME IMPROVEMENT THIS AFTN WITH MANY AREAS
SEEING VFR CIGS. LATER SAT NIGHT AS THE LLVL WINDS AND WARM
ADVECTION INCREASE...CHANCES LOOK GOOD FOR AN IFR DECK. LIGHT RAIN
IS ALSO POSSIBLE LATE TONIGHT...ESPECIALLY AROUND KAVL.
OUTLOOK...THE APPROACH OF THE NEXT STRONG COLD FRONT WILL BRING
INCREASING RAIN CHANCES AND LIKELY RESTRICTIONS ON SUNDAY INTO EARLY
MONDAY. A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 93% HIGH 83% MED 79% MED 75%
KGSP MED 76% HIGH 90% MED 79% MED 78%
KAVL MED 65% HIGH 83% HIGH 94% HIGH 96%
KHKY MED 79% HIGH 84% HIGH 97% HIGH 100%
KGMU MED 77% HIGH 90% HIGH 81% HIGH 81%
KAND MED 79% HIGH 83% MED 77% MED 78%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY/PM
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
641 AM EST SAT NOV 16 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE REGION SUNDAY
NIGHT INTO EARLY MONDAY...FOLLOWED BY STRONG HIGH PRESSURE BUILDING
OVER THE REGION THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 AM EST SATURDAY...UPPED MIN TEMPS A FEW DEGREES AS
WIDESPREAD LOW CLOUDS HAVE RESULTED IN NEAR STEADY TEMPS THE BEST
SEVERAL HOURS. DEWPOINTS ARE ALSO A LITTLE HIGHER THAN WHAT WAS IN
THE GRIDS AND THOSE HAVE BEEN BUMPED UP AS WELL. IT WILL BE
INTERESTING TO SEE IF FOG BECOMES MORE WIDESPREAD AFTER SUNRISE.
AS OF 245 AM EST SATURDAY...WIDESPREAD LOW CLOUDS AND AREAS OF FOG
WILL GRADUALLY LIFT AND PARTIALLY BURN OFF THIS MORNING. SO FAR THE
FOG HAS BEEN WELL SHORT OF ADVISORY CRITERIA. WITH ALL SITES
REPORTING A CEILING AT THIS HOUR...IT WOULD APPEAR THAT ANY DENSE
FOG THROUGH MID MORNING WILL BE ISOLATED. SCATTERED PATCHES OF RAIN
CONTINUE ATTM OVER WRN NC...BUT A WEAKENING LOW LEVEL WIND FIELD AND
NVA ALOFT SHOULD BRING THAT TO AN END IN A COUPLE HOURS. OTHERWISE
IT WILL BE A QUIET WEATHER DAY AS HEIGHTS RISE OVER THE REGION AHEAD
OF STRONG TROUGH DIGGING INTO THE CENTRAL HIGH PLAINS STATES.
LOW LEVEL WINDS WILL INCREASE IN SPEED TONIGHT AHEAD OF THAT
DEEPENING TROUGH. THE NAM H8 WINDS INCREASE TO AROUND 30 KTS. THE
STRENGTHENING WINDS AND INCREASING LLVL WARM ADVECTION AS A THERMAL
RIDGE MOVES IN FROM THE WEST WILL BE SUFFICIENT FOR ANOTHER ROUND OF
UPSLOPE ENHANCED LIGHT RAIN AND DRIZZLE. THE BULK OF THE PCPN SHOULD
BE CONFINED TO THE MOUNTAINS AND WRN FOOTHILLS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AT 230 AM EST SATURDAY...AN UPPER RIDGE WILL BE OFF THE EAST COAST
ON SATURDAY...WHILE AN UPPER TROUGH WILL BE OVER THE CENTER OF THE
NATION. THE DEAMPLIFYING TROUGH AXIS WILL PROGRESS TO THE CENTRAL
AND SOUTHERN APPALACHIANS BY BY MONDAY...MOVING OFF THE EAST COAST
ON MONDAY NIGHT.
SURFACE HIGH PRESSURE WIL WEAKEN ALONG THE EAST COAST ON SUNDAY...
WHILE A COLD FRONT CROSSES THE MS RIVER VALLEY. MOIST ISENTROPIC
UPGLIDE FLOW WILL PRECEDE THE FRONT ON SUNDAY AND SUNDAY NIGHT...
HOWEVER LOW LEVEL UPSLOPE FLOW WILL WEAKEN AS WINDS VEER AND BECOME
PARALLEL TO THE BLUE RIDGE. FRONTAL PASSAGE OVER OUR AREA IS
EXPECTED TO OCCUR LATE SUNDAY NIGHT AND EARLY MONDAY. WHILE BOTH THE
NAM AND GFS SHOW SHEAR CROSSING THE AREA WITH THE FRONT...NAM CAPE
IS MARGINAL...AND GFS CAPE MUCH WEAKER. THE SITUATION WILL NEED TO
BE MONITORED FOR THE POSSIBILITY OF A LOW CAPE...HIGH SHEAR
ENVIRONMENT. PRECIPITATION IS NOT EXPECTED TO BE EXCESSIVE...WITH
PERHAPS A BIT MORE THAN ONE INCH OF RAINFALL ALONG THE SOUTH FACING
BLUE RIDGE ESCARPMENT.
TEMPERATURES WILL WARM ABOVE NORMAL AHEAD OF THE FRONT...WITH A
REDUCED DIURNAL RANGE IN CLOUDS AND PRECIPITATION. TEMPERATURES WILL
WARM EVEN FURTHER ABOVE NORMAL MONDAY IN DOWNSLOPE FLOW BEHIND THE
FRONT....BUT WILL FALL BELOW NORMAL MONDAY NIGHT IN COLD ADVECTION
WITH WINDS DIMINISHING AND VEERING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 155 AM EST SATURDAY...TUESDAY THROUGH FRIDAY NIGHT...MEDIUM
RANGE MODELS SHOW HIGH PRESSURE CENTERED OVER ILLINOIS AT 12Z
TUESDAY WITH PRESSURE GRADIENT EASING OVER THE CAROLINAS. BY 00Z WED
THE CENTER OF THE HIGH IS OVER THE EASTERN GREAT LAKES WITH LOW
LEVEL WIND FLOW FOR OUR AREA BEING GENERALLY NE. AS THIS HIGH MOVES
OFF THE NEW ENGLAND COAST THURSDAY AFTERNOON...THE WIND FLOW BECOMES
MORE EAST TO SE AND TEMPS RISE A BIT FROM JANUARY TYPE TEMPS TO JUST
A FEW DEGREES BELOW NORMAL ON FRIDAY. THE GFS HAS A SURFACE LOW
FORMING OVER EAST TEXAS FRIDAY NIGHT AND MOVING NE WHILE THE ECMWF
HAS A LESS VIGOROUS TROUGH AND SURFACE DEVELOPMENT. BOTH OF THESE
MODELS HAVE AT LEAST SOME LIGHT PRECIP MOVING INTO THE WESTERN NC
MTNS BY LATE FRIDAY NIGHT. THEREFORE...I HAVE INTRODUCED SLIGHT POPS
FOR THAT AREA IN THE EXTRA PERIOD OF FRIDAY NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...SKIES HAVE ACTUALLY CLEARED ABOUT 20 MILES TO THE
SOUTHEAST OF THE AIRFIELD. HOWEVER...THE LLVL FLOW IS WEAKLY OUT OF
THE SOUTHWEST AND CIGS BETWEEN 005-007 SHOULD LAST THROUGH ABOUT 15
UTC. THE NAM MODEL SOUNDINGS IMPLY CONDITIONS COULD IMPROVE
EARLIER...THE RAP LATER. WITH THE VERY LIGHT LLVL WINDS AND FAIRLY
WEAK INVERSION...I DON/T SEE THE IFR LEVEL CIGS HANGING AROUND MUCH
BEYOND 15 UTC...BUT I/M NOT TERRIBLY CONFIDENT ABOUT THIS. A PERIOD
OF VFR CONDITIONS IS EXPECTED TO DEVELOP THIS AFTERNOON...WITH
STRATUS RETURNING AGAIN TONIGHT. IN FACT...WITH A STRONGER WIND
FIELD AND BETTER WARM ADVECTION...I THINK THE CHANCES OF AN IFR DECK
ARE PRETTY GOOD.
ELSEWHERE...IFR CONDITIONS PREVAIL ACROSS THE REGION THIS MORNING.
EXPECTING CIGS TO HOLD GENERALLY BETWEEN 007-010 OVER THE NEXT FEW
HOURS. HOWEVER...THERE HAVE BEEN BREAKS IN THE IFR WITH AN MVFR DECK
ABOVE THAT. ADDED A TEMPO GROUP TO ACCOUNT FOR THIS AT ALL SITES
EXCEPT KAVL. VSBYS SHOULD GENERALLY BE IN THE MVFR RANGE AT THE
UPSTATE SITES...AND A LITTLE LOWER IN NC. IT IS POSSIBLE THAT
CONDITIONS WILL WORSEN AFTER SUNRISE WITH THE MOIST LOW LEVELS. THE
LLVL WINDS LOOK TOO WEAK TO SUPPORT STRATUS...CAUSING ME TO BE
CONCERNED ABOUT INCREASING AMOUNTS OF FOG AFTER 12 UTC. I DON/T SEE
ANYTHING TO REALLY HANG MY HAT ON IN THIS REGARD...WHICH IS WHY THE
TAFS SIMPLY REFLECT THE PREVAILING CONDITIONS FOR ANOTHER 3 HOURS OR
SO. THERE SHOULD BE SOME IMPROVEMENT THIS AFTN WITH MANY AREAS
SEEING VFR CIGS. LATER SAT NIGHT AS THE LLVL WINDS AND WARM
ADVECTION INCREASE...CHANCES LOOK GOOD FOR AN IFR DECK. LIGHT RAIN
IS ALSO POSSIBLE LATE TONIGHT...ESPECIALLY AROUND KAVL.
OUTLOOK...THE APPROACH OF THE NEXT STRONG COLD FRONT WILL BRING
INCREASING RAIN CHANCES AND LIKELY RESTRICTIONS ON SUNDAY INTO EARLY
MONDAY. A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT MED 74% HIGH 92% HIGH 87% MED 73%
KGSP MED 62% HIGH 88% MED 71% HIGH 82%
KAVL MED 66% MED 79% MED 75% HIGH 93%
KHKY LOW 55% HIGH 86% HIGH 83% HIGH 95%
KGMU MED 61% HIGH 88% MED 68% HIGH 80%
KAND LOW 55% HIGH 85% MED 71% MED 73%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA
EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE
SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST
THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID
LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO
WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER
SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST
SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT
TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF
PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO
SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW
PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS
STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW
CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH
DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY
GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL
THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY.
REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST
CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT
ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE
IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH
WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT
REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP
BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK.
ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY
MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS
CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE
INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE
DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT
PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD
THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN
BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE
MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS
HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS
TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST
UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST
CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER
MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT
THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY
WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD
BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY.
WILL CONTINUE TO MONITOR.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH
TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE
FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS
THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD
OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE
DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE
FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A
SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER
RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER
CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL.
THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION
BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW
WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT
FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW
ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG
BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12
HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES
STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS
STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH
OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS
POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE
EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW
MORNING...AS WELL.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR SHOULD PREVAIL TODAY AND TONIGHT AT KMBG...KPIR AND KABR.
THERE MAY BE A COUPLE SPRINKLES OR FLURRIES AT KPIR AND KABR AND
ALONG A LINE BETWEEN THESE TWO TERMINALS THROUGH ABOUT MID-DAY
TODAY. BUT...THIS SHOULD NOT IMPACT CIGS OR VISBIES.
KATY CONTINUES TO REMAIN THE CONCERN FOR SUB-VFR CONDITIONS.
SURFACE TO TOP-OF-THE-BOUNDARY-LAYER MOISTURE CONTINUES TO
INCREASE THIS MORNING ON LIGHT SOUTH WINDS. UPSTREAM FROM
KATY...SITES ACROSS SERN SOUTH DAKOTA AND SWRN MINNESOTA ARE
REPORTING IFR CIGS AND IN SOME CASES MVFR/IFR VISBIES. SEEMS
INCREASINGLY PROBABLE THAT KATY WILL BE DOWN INTO SOME FORM OF
SUB-VFR FLYING CONDITIONS WITHIN THE NEXT 3 TO 6 HOURS. THERE IS
ALSO A CHANCE FOR SOME RAIN AT KATY MAINLY LATER THIS AFTERNOON
FOR A FEW HOURS AS A LOW PRESSURE SYSTEM LIFTS NEWD ACROSS THE
REGION.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
533 AM CST SAT NOV 16 2013
.DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
DIFFICULT FORECAST. MVFR TO IFR SHOULD IMPROVE SLOWLY THROUGH THE
MID AND LATE MORNING. ISOLATED SHOWERS WERE DEVELOPING OVER THE
GULF WATERS SOUTH OF FREEPORT...HOWEVER THE MODEL SOUNDINGS
INDICATE A CAP WILL BE IN PLACE AND DO NOT EXPECT THESE TO BECOME
MORE WIDESPREAD. AS THE CEILINGS LIFT...BREEZY CONDITIONS MAY
DEVELOP THIS AFTERNOON. ANOTHER ROUND OF AT LEAST MVFR TONIGHT.
40
&&
.PREV DISCUSSION... /ISSUED 402 AM CST SAT NOV 16 2013/
DISCUSSION...
PATCHY FOG...LOCALLY DENSE IN A FEW SPOTS...WILL PERSIST THROUGH
MID MORNING BEFORE ERODING. DEEP MOISTURE REMAINS IN PLACE. NOT
MUCH IN THE WAY OF A LOW LEVEL FOCUS AND UPPER LEVEL SUPPORT BUT
THE MOISTURE LEVELS ARE SO HIGH THAT FEEL SOME SHOWERS WILL
DEVELOP DURING THE DAY. BOTH THE RAP AND TEXAS TECH WRF SHOW
SHOWERS DEVELOPING THIS AFTN SO WILL ADD 20 POPS BACK TO THE
FCST. OVERNIGHT LOWS ON SUN MORNING WILL BE UNSEASONABLY WARM AND
MINS WILL ONLY FALL INTO THE UPPER 60S. W-SW WINDS JUST OFF THE
SURFACE COUPLED WITH THE WARM START SHOULD YIELD MAX TEMPS IN THE
MID 80S. RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. FCST
SOUNDINGS ON SUNDAY SHOW AN ERODING CAP AND PWATS BETWEEN 1.6 AND
1.8 INCHES SO WILL MAINTAIN 20 POPS ON SUNDAY.
A COLD FRONT WILL CROSS SE TX ON MONDAY. GFS LOOKS A BIT FAST WITH
THIS FEATURE AND PREFER THE SLOWER NAM/ECMWF SOLN. MSTR POOLS
AHEAD OF THE BOUNDARY AND SCT SHRA/TSRA WILL BE POSSIBLE ALONG THE
COAST AND PARTS OF THE SOUTHERN CWA. AM CARRYING CHC POPS FOR THE
COAST ON MONDAY MORNING BUT FEEL THESE MIGHT BE A TAD LOW. MSTR
LEVELS NEVER REALLY DROP OFF THIS WEEK AND AN UPPER LEVEL
DISTURBANCE COULD BRING MORE SHOWERS ON TUESDAY AFTN. SW FLOW
ALOFT ON THURSDAY WILL BRING A DISTURBANCE ACROSS SE TX. THIS
FEATURE COUPLED WITH PWATS AROUND 1.6 INCHES SHOULD AGAIN YIELD
MORE PRECIP. MSTR ON THE BACKSIDE OF A RETREATING SURFACE RIDGE
WILL CONTINUE TO DRAW DEEPER MSTR INTO SE TX THU/FRI. A COLD FRONT
WILL CROSS SE TX ON FRI AND RAIN CHANCES WILL CONTINUE. A DEEP
UPPER LEVEL LOW WILL REMAIN WEST OF THE REGION THROUGH NEXT
WEEKEND. ISENTROPIC UPGLIDE WILL BE MAXIMIZED WITH NNE SFC WINDS
BEING OVERRUN BY SW WINDS ALOFT. NEXT WEEKEND LOOKS RAINY AND
KIND OF RAW. MAX TEMPS WILL STRUGGLE TO REACH 50 DEGREES IF THE
ECMWF VERIFIES. LEANED TOWARD THE ECMWF NEXT FRI-SUN BUT MODELS
DIFFER WITH TIMING AND RUN TO RUN CONSISTENCY HAS BEEN POOR. 43
CLIMATE...
RECORD HIGH TEMPERATURES ARE POSSIBLE ON SUNDAY. RECORDS FOR
SUNDAY NOV 17TH ARE THE FOLLOWING:
CURRENT RECORDS FORECAST
VALUES
IAH 84 - 1985 86
CLL 85 - 1921 86
MARINE...
LONG PERIOD SWELLS WERE OCCURRING AT BUOY 42019. MAY NEED TO UPGRADE
TO A SMALL CRAFT ADVISORY IF THESE CONTINUE AND WILL UPDATE IF
NEEDED. OTHERWISE...WINDS WILL GRADUALLY DECREASE LATER TODAY AND
TONIGHT AS A COLD FRONT MOVES TOWARD THE COAST. THE FRONT IS
EXPECTED TO PUSH OFF THE COAST MONDAY MORNING WITH INITIAL POST
FRONTAL WINDS OUT OF THE NORTH. THE MODELS ARE CONSISTENT WITH
MODERATE TO STRONG NORTHEAST WINDS DEVELOP MONDAY NIGHT AND TUESDAY.
AS HIGH PRESSURE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY INTO THE
EASTERN SEABOARD...EXPECT SOUTHEAST WINDS TO DEVELOP BY WEDNESDAY.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 81 71 86 61 74 / 20 20 20 10 10
HOUSTON (IAH) 81 72 86 66 77 / 20 20 20 20 20
GALVESTON (GLS) 77 70 78 69 74 / 20 20 20 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
243 PM CST SAT NOV 16 2013
.DISCUSSION...
1230 PM CST
ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER
COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT
WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE
TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z
REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA
SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE
POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE
TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE
ADVECTION.
PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO
SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER
PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND.
UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM.
MTF
//PREV DISCUSSION...
815 AM CST
FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING.
THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA.
ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES
HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON
THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE.
THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF
UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE
TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE
CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS
TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY
EARLY AFTERNOON AND SPREADING EAST FROM THERE.
MTF
//PREV DISCUSSION...
333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY.
IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA
SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE.
DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING
WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER
50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST
AHEAD OF THE COLD FRONT SUNDAY MORNING.
LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS
EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR
TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP
SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED
JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE
ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER
WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE
INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES.
THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING
WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT
EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE
SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY
RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A
LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS
WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE.
DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS
AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS
WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY
IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S
TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF
THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY
BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS
EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN
CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING.
A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND
QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY
DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES
LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE
ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID
SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE
EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW...
DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO
SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME...
ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD
FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS
OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO
WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS
UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING
SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY
ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG
STORMS CAN/T BE RULED OUT.
ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS
LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER
OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY
IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS
NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS
STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND
WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT
LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE
OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL
UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP...
JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST
INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS
MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE
I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN
CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE
MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE
ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO
ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A
TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE
THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER
VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION
WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE
LOCALIZED DEPENDING ON CONVECTIVE COVERAGE.
STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE
30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR
WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME
OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT
WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY...
LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS
WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/
COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES.
THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER
SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY.
HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH
TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY
SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS
IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C
TO +15C RANGE.
WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE
ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH
PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND
THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED.
WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S...
MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE
AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL
FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY
WARMER.
HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS
TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO
NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS
EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO
THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW
SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH
THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS
AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND
WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN
PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF
FRONT AND END TIME OF PRECIP. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT.
* SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH
EARLY EVE.
* SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS
EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON
SUNDAY AFTERNOON.
* LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO
50 KT OR STRONGER.
* TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM
POTENTIAL THIS MORNING AND EARLY AFTERNOON.
//DISCUSSION...UPDATED 18Z...
INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO
INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE
POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY
RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE
SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL
INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW
PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE
THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE
PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO
OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP
OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD.
THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH
MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD
BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY
WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER
THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING
WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+.
MTF
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE.
* HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE.
* HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH
18Z SUNDAY...MEDIUM CONFIDENCE AFTER.
* HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER
THIS EVE.
* MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH
CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS
THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE.
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN
AT NIGHT. MAINLY VFR.
MDB
&&
.MARINE...
215 PM CST
A STRONG STORM SYSTEM WILL IMPACT THE GREAT LAKES REGION OVER THE
WEEKEND BRINGING PERIODS OF GALES WITH STORM FORCE WINDS A
POSSIBILITY ON THE BACK END OF THE SYSTEM. BROAD AREA OF LOW
PRESSURE IS BEGINNING TO CONSOLIDATE OVER THE NORTHERN PLAINS
TODAY...BUT WILL SIGNIFICANTLY DEEPEN OVER WISCONSIN EARLY SUNDAY
AFTERNOON...THEN CONTINUE TO DEEPEN AS IT MOVES ACROSS NORTHERN LAKE
MICHIGAN SUNDAY EVENING. SOUTHERLY GALES WILL CONTINUE THROUGH THE
OVERNIGHT HOURS INTO EARLY SUNDAY. THESE WINDS WILL TRANSPORT MOIST
AIR NORTH OVER THE WATERS WHICH IS EXPECTED TO LEAD TO AREAS OF FOG
DEVELOPMENT. IT IS UNCERTAIN HOW WIDESPREAD OR DENSE THE FOG WILL
BE...BUT A FOG ADVISORY IS NOT OUT OF THE REALM OF POSSIBILITY.
WINDS ARE EXPECTED TO EASE SLIGHTLY BELOW GALES DURING PORTIONS OF
THE DAY SUNDAY...ESPECIALLY THE NORTHERN HALF OF THE LAKE WHERE THE
GRADIENT WILL WEAKEN NEAR THE LOW CENTER. AFTER THE LOW AND
ATTENDANT COLD FRONT PUSH EAST OF THE LAKE SUNDAY EVENING...WINDS
WILL TURN WESTERLY AND QUICKLY RAMP BACK UP TO STRONG GALES OF 40 TO
45 KT...WITH OCCASIONAL STORM FORCE GUSTS STILL A POSSIBILITY. WINDS
WILL SLOWLY TAPER MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS
THE MISSISSIPPI VALLEY...AND SHOULD DROP BELOW GALES BY MID
AFTERNOON. WINDS BACK TO THE SOUTHWEST ON TUESDAY AS LOW PRESSURE
MOVES EAST ACROSS THE CANADIAN PRAIRIES. SOUTHERLY GALES MAY BE
POSSIBLE AGAIN ON WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...10 AM SUNDAY TO
8 PM SUNDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...10 AM
SUNDAY TO 8 PM SUNDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 4
AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
216 PM CST SAT NOV 16 2013
.DISCUSSION...
1230 PM CST
ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER
COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT
WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE
TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z
REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA
SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE
POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE
TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE
ADVECTION.
PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO
SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER
PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND.
UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM.
MTF
//PREV DISCUSSION...
815 AM CST
FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING.
THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA.
ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES
HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON
THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE.
THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF
UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE
TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE
CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS
TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY
EARLY AFTERNOON AND SPREADING EAST FROM THERE.
MTF
//PREV DISCUSSION...
333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY.
IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA
SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE.
DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING
WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER
50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST
AHEAD OF THE COLD FRONT SUNDAY MORNING.
LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS
EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR
TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP
SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED
JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE
ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER
WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE
INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES.
THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING
WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT
EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE
SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY
RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A
LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS
WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE.
DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS
AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS
WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY
IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S
TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF
THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY
BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS
EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN
CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING.
A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND
QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY
DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES
LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE
ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID
SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE
EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW...
DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO
SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME...
ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD
FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS
OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO
WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS
UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING
SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY
ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG
STORMS CAN/T BE RULED OUT.
ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS
LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER
OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY
IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS
NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS
STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND
WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT
LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE
OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL
UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP...
JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST
INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS
MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE
I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN
CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE
MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE
ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO
ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A
TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE
THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER
VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION
WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE
LOCALIZED DEPENDING ON CONVECTIVE COVERAGE.
STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE
30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR
WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME
OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT
WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY...
LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS
WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/
COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES.
THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER
SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY.
HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH
TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY
SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS
IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C
TO +15C RANGE.
WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE
ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH
PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND
THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED.
WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S...
MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE
AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL
FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY
WARMER.
HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS
TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO
NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS
EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO
THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW
SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH
THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS
AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND
WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN
PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF
FRONT AND END TIME OF PRECIP. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT.
* SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH
EARLY EVE.
* SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS
EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON
SUNDAY AFTERNOON.
* LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO
50 KT OR STRONGER.
* TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM
POTENTIAL THIS MORNING AND EARLY AFTERNOON.
//DISCUSSION...UPDATED 18Z...
INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO
INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE
POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY
RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE
SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL
INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW
PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE
THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE
PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO
OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP
OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD.
THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH
MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD
BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY
WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER
THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING
WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+.
MTF
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE.
* HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE.
* HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH
18Z SUNDAY...MEDIUM CONFIDENCE AFTER.
* HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER
THIS EVE.
* MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH
CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS
THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE.
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN
AT NIGHT. MAINLY VFR.
MDB
&&
.MARINE...
215 PM CST
A STRONG STORM SYSTEM WILL IMPACT THE GREAT LAKES REGION OVER THE
WEEKEND BRINGING PERIODS OF GALES WITH STORM FORCE WINDS A
POSSIBILITY ON THE BACK END OF THE SYSTEM. BROAD AREA OF LOW
PRESSURE IS BEGINNING TO CONSOLIDATE OVER THE NORTHERN PLAINS
TODAY...BUT WILL SIGNIFICANTLY DEEPEN OVER WISCONSIN EARLY SUNDAY
AFTERNOON...THEN CONTINUE TO DEEPEN AS IT MOVES ACROSS NORTHERN LAKE
MICHIGAN SUNDAY EVENING. SOUTHERLY GALES WILL CONTINUE THROUGH THE
OVERNIGHT HOURS INTO EARLY SUNDAY. THESE WINDS WILL TRANSPORT MOIST
AIR NORTH OVER THE WATERS WHICH IS EXPECTED TO LEAD TO AREAS OF FOG
DEVELOPMENT. IT IS UNCERTAIN HOW WIDESPREAD OR DENSE THE FOG WILL
BE...BUT A FOG ADVISORY IS NOT OUT OF THE REALM OF POSSIBILITY.
WINDS ARE EXPECTED TO EASE SLIGHTLY BELOW GALES DURING PORTIONS OF
THE DAY SUNDAY...ESPECIALLY THE NORTHERN HALF OF THE LAKE WHERE THE
GRADIENT WILL WEAKEN NEAR THE LOW CENTER. AFTER THE LOW AND
ATTENDANT COLD FRONT PUSH EAST OF THE LAKE SUNDAY EVENING...WINDS
WILL TURN WESTERLY AND QUICKLY RAMP BACK UP TO STRONG GALES OF 40 TO
45 KT...WITH OCCASIONAL STORM FORCE GUSTS STILL A POSSIBILITY. WINDS
WILL SLOWLY TAPER MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS
THE MISSISSIPPI VALLEY...AND SHOULD DROP BELOW GALES BY MID
AFTERNOON. WINDS BACK TO THE SOUTHWEST ON TUESDAY AS LOW PRESSURE
MOVES EAST ACROSS THE CANADIAN PRAIRIES. SOUTHERLY GALES MAY BE
POSSIBLE AGAIN ON WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...10 AM SUNDAY TO
8 PM SUNDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...10 AM
SUNDAY TO 8 PM SUNDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 4
AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1233 PM CST SAT NOV 16 2013
.DISCUSSION...
1230 PM CST
ONLY SMALL CHANGES MADE TO THIS AFTERNOON FORECAST. SHOWER
COVERAGE WILL FURTHER INCREASE AHEAD OF THE WELL-DEFINED SHORT
WAVE TROUGH LIFTING NORTHEAST FROM THE NE/IA BORDER. THE MOISTURE
TRANSPORT NOSE ALONG WITH ELEVATED STEEP LAPSE RATES SEEN ON 12Z
REGIONAL SOUNDINGS WILL CONTINUE TO ADVECT OVER THE AREA
SUPPORTING AND REPLENISHING THIS ACTIVITY INTO EARLY EVE. SEVERE
POTENTIAL REMAINS VERY LOW WITH THIS. TEMPERATURES SHOULD CONTINUE
TO WARM ESPECIALLY OUTSIDE OF THE SHOWERS...JUST SIMPLY BY PURE
ADVECTION.
PRONOUNCED REGIONAL SEVERE THREAT CONTINUES FOR LATE TONIGHT INTO
SUNDAY AFTERNOON. NEW SPC MODERATE RISK DOES INCLUDE A LARGER
PORTION OF THE FORECAST AREA...INCLUDING ALL OF CHICAGOLAND.
UPDATED DISCUSSION ON THIS WILL BE POSTED BY 300 PM.
MTF
&&
.PREV DISCUSSION...
815 AM CST
FORECAST UPDATED TO ADD DRIZZLE IN THROUGH THIS MORNING.
THE LOW-LEVEL MOISTURE SURGE CONTINUES TO RETURN OVER THE AREA.
ISENTROPIC ASCENT ON THE RAP ANALYSIS OF 285K AND 290K SURFACES
HAS RAPIDLY SATURATED AND LOOKS TO BE THE ROOT OF THIS. EVEN ON
THE 12Z ILX RAOB...THE PROFILE WAS VERY SUGGESTIVE OF DRIZZLE.
THIS COULD CONTINUE INTO THIS AFTERNOON BASED ON THE EXTENT OF
UPSTREAM OBS ACROSS CENTRAL AND SOUTHERN IL. SOUTH WINDS CONTINUE
TO BRING WARM AIR ADVECTION SO TEMPERATURES WILL INCH UPWARD. THE
CHANCE FOR TRUE SHOWERS AND POSSIBLY SOME STORMS TODAY STILL LOOKS
TO ARRIVE WITH A SHORT WAVE ACROSS THE WESTERN FORECAST AREA BY
EARLY AFTERNOON AND SPREADING EAST FROM THERE.
MTF
//PREV DISCUSSION...
333 AM...FORECAST FOCUS REMAINS POTENTIAL SEVERE WEATHER OUTBREAK
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY ON SUNDAY.
IN THE SHORT TERM...LOW CLOUDS HAVE STREAMED NORTH ACROSS THE AREA
SIGNALING THE BEGINNING OF A SURGE OF LOW LEVEL MOISTURE.
DEWPOINTS SLOWLY CREEPING INTO THE LOWER 40S EARLY THIS MORNING
WILL CONTINUE TO RISE INTO THE LOWER/MID 50S THIS AFTERNOON...UPPER
50S TONIGHT AND LIKELY POOL IN THE LOWER TO PERHAPS MID 60S JUST
AHEAD OF THE COLD FRONT SUNDAY MORNING.
LOW PRESSURE OVER NEBRASKA WILL LIFT NORTH TO MINNESOTA BY THIS
EVENING AND AS IT DOES...AN UPPER LEVEL WAVE WILL MOVE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING. MUCH OF THE EASTERN HALF OR
TWO THIRDS WILL LIKELY REMAIN DRY THIS MORNING WITH PRECIP
SPREADING ACROSS THE WESTERN CWA BY LATE MORNING. HAVE INCLUDED
JUST A CHANCE OF THUNDERSTORMS WITH THE STRONGER/CONVECTIVE
ELEMENTS BUT CONFIDENCE REGARDING HOW WIDESPREAD LIGHTNING/THUNDER
WILL BECOME IS SOMEWHAT LOW AND THUNDER COVERAGE MAY NEED TO BE
INCREASED BASED ON SHORT TERM TRENDS ONCE PRECIP DEVELOPS/ARRIVES.
THIS ACTIVITY SHOULD MOVE NORTHEAST OF THE AREA BY MID/LATE EVENING
WITH A POSSIBLE LULL IN ACTIVITY INTO THE EARLY MORNING HOURS. NOT
EXPECTING ANY OF THE THUNDERSTORMS DURING THIS FIRST WAVE TO BE
SEVERE. SOME COULD PRODUCE STRONG/GUSTY WINDS AS WELL AS HEAVY
RAIN. THOUGH STORM MOTION SHOULD BE SUFFICIENTLY FAST TO PREVENT A
LONG DURATION HEAVY RAIN IN ANY ONE LOCATION. RAINFALL AMOUNTS
WITH THIS WAVE APPEAR TO BE IN THE 0.5 TO 0.75 RANGE.
DESPITE MAINLY CLOUDY SKIES TODAY AND THEN PRECIP THIS
AFTERNOON...WITH THE NOTED SURGE IN LOW LEVEL MOISTURE...TEMPS
WILL CONTINUE TO CLIMB THROUGH THE DAY WITH CURRENT TEMPS ALREADY
IN THE LOWER 50S ACROSS SOUTHERN IL. THUS...HIGHS IN THE UPPER 50S
TO LOWER 60S LOOK ON TRACK AND MUCH OF THE SOUTHERN THIRD/HALF OF
THE CWA MAY NOT SEE PRECIP UNTIL LATE THIS AFTERNOON AND IF ANY
BREAKS DEVELOP...THIS WILL AID TEMPS FURTHER. AS PRECIP ENDS THIS
EVENING...POSSIBLE FOR SOME LOCATIONS...ESPECIALLY NORTHERN
CWA...TO CONTINUE TO WARM WITH HIGHS BEING REACHED IN THE EVENING.
A SECOND LOW THEN DEVELOPS OVER EASTERN COLORADO TONIGHT AND
QUICKLY SHIFTS EAST TO IOWA BY SUNDAY MORNING...THEN RAPIDLY
DEEPENS AS IT ABSORBS THE FIRST LOW OVER MINNESOTA...AND REACHES
LAKE SUPERIOR BY SUNDAY EVENING. A STRONG COLD FRONT WILL RACE
ACROSS THE CWA FROM MID/LATE SUNDAY MORNING THROUGH EARLY/MID
SUNDAY AFTERNOON. ANOTHER WAVE OF THUNDERSTORMS IS POSSIBLE IN THE
EARLY MORNING HOURS OF SUNDAY AHEAD OF THIS SECOND LOW...
DEVELOPING OVER EASTERN IOWA AND NORTHWEST IL THEN MOVING INTO
SOUTHERN WI...MOSTLY LIKELY BY SUNRISE. AT THE SAME TIME...
ADDITIONAL THUNDERSTORMS COULD BE DEVELOPING AHEAD OF THE COLD
FRONT ACROSS PARTS OF IOWA/MISSOURI. ANY OF THESE THUNDERSTORMS
OVERNIGHT INTO EARLY SUNDAY MORNING COULD BECOME SEVERE. BUT TO
WHAT EXTENT AND HOW WIDESPREAD ANY SEVERE WEATHER WOULD BECOME IS
UNCERTAIN. HOWEVER...WITH SUCH WARM/MOIST LOW LEVELS...A DEEPENING
SURFACE LOW AND WHAT COULD END UP BEING A WARM FRONTAL BOUNDARY
ACROSS THE NORTHERN CWA...THE THREAT OF A TORNADO WITH ANY STRONG
STORMS CAN/T BE RULED OUT.
ANOTHER BRIEF LULL IS EXPECTED SUNDAY MORNING BEFORE WHAT APPEARS
LIKE IT COULD BE THE BEGINNING OF A WIDESPREAD SEVERE WEATHER
OUTBREAK DEVELOPS. WINDS THROUGH THE ENTIRE COLUMN REMAIN VERY
IMPRESSIVE WITH 50 KNOTS AS LOW AS 900MB SUNDAY MORNING. AS
NOTED...WHILE THE WARM/MOIST CONDITIONS WILL HELP/AID STORMS
STAYING SURFACE BASED...EXPECT QUITE A BIT OF CLOUD COVER...AND
WHILE HAVE TRIED TO SHOW SOME PARTLY/MOSTLY CLOUDY CONDITIONS AT
LEAST ACROSS THE SOUTHEAST CWA SUNDAY MORNING...ITS POSSIBLE
OVERCAST CONDITIONS WILL PERSIST UNTIL FROPA. ADDITIONAL
UNCERTAINTY REMAINS WITH WHERE/WHEN THUNDERSTORMS WILL DEVELOP...
JUST WEST OF THE CWA...OVER THE CWA...EASTERN CWA/NORTHWEST
INDIANA. ENTIRE CWA IS NOW INCLUDED IN SLIGHT RISK PER THIS
MORNING/S SPC DAY2 OUTLOOK WITH MODERATE RISK EAST OF THE
I-55/I-57 CORRIDOR. POTENTIAL IS CERTAINLY HIGHER OVER THE EASTERN
CWA BUT EVEN FROM THIS DISTANCE WILL BE INCLUDING SEVERE
MENTION/DAMAGING WINDS IN THE ZONES/GRIDS. THUNDERSTORMS WILL BE
ENDING FROM WEST TO EAST DURING THE MID/LATE AFTERNOON AND ALSO
ATTEMPTED TO INCLUDE THIS TIMING IN THE GRIDS. THE THREAT OF A
TORNADO OR TWO WILL REMAIN SUNDAY BUT DAMAGING WINDS APPEAR TO BE
THE PRIMARY SEVERE WEATHER THREAT. DESPITE PRECIPITABLE WATER
VALUES ONLY AROUND AN INCH...EXPECT VERY EFFICIENT RAIN PRODUCTION
WITH ANOTHER 0.5-0.75 INCHES POSSIBLE...ALTHOUGH PERHAPS MORE
LOCALIZED DEPENDING ON CONVECTIVE COVERAGE.
STRONG WINDS FROM THE SOUTH WILL DEVELOP TODAY WITH GUSTS INTO THE
30-35 MPH RANGE POSSIBLE. STILL APPEARS THERE COULD BE A 3-6 HOUR
WINDOW THIS EVENING OF GUSTS 40+ MPH BEFORE WINDS DIMINISH SOME
OVERNIGHT...WHILE CLOSE TO WIND ADVISORY CRITERIA...NOT SURE IT
WILL BE REACHED AND NO HEADLINES THROUGH TONIGHT. BY SUNDAY...
LOW LEVEL WINDS ARE WELL INTO ADVISORY CRITERIA AND SOME OF THIS
WILL LIKELY MIX TO THE SURFACE ESPECIALLY JUST BEHIND THE STORMS/
COLD FRONT AS COLD ADVECTION IS AIDED BY LARGE PRESSURE RISES.
THIS IS THIRD PERIOD AND A BIT EARLY FOR AN ADVISORY AND LATER
SHIFTS WILL NEED TO ASSESS WIND POTENTIAL/HEADLINES FOR SUNDAY.
HAVE CONTINUED INCREASING HIGH TEMPS FOR SUNDAY WITH MID 60S NORTH
TO UPPER 60S FROM I-55 SOUTH AND ITS QUITE POSSIBLE SOME AREAS MAY
SEE TEMPS TAG 70 AHEAD OF THE FRONT...ESPECIALLY WITH ANY BREAKS
IN THE OVERCAST AS 850MB TEMPS ARE NOW EXPECTED TO BE IN THE +12C
TO +15C RANGE.
WRAP AROUND SHOWERS WILL BE POSSIBLE SUNDAY EVENING BUT SHOULD BE
ENDING FAIRLY QUICKLY WITH CLEARING SKIES OVERNIGHT AS HIGH
PRESSURE BUILDS INTO THE REGION MONDAY AFTERNOON/MONDAY NIGHT AND
THIS HIGH IS MOVING FASTER THAN PREVIOUS MODELS HAD SUGGESTED.
WHILE IT WILL TURN MUCH COLDER MONDAY NIGHT WITH LOWS IN THE 30S...
MONDAY MAY END UP BEING MAINLY SUNNY WITH DIMINISHING WINDS IN THE
AFTERNOON AND TEMPS REBOUNDING BACK INTO THE MID 40S. STILL WILL
FEEL MUCH COLDER COMPARED TO SUNDAY...BUT THE TREND IS SLIGHTLY
WARMER.
HAVE CONTINUED THE WARMING TREND TUESDAY THROUGH THURSDAY AS WINDS
TURN SOUTHERLY SOONER ON THE BACK SIDE OF THE DEPARTING HIGH. ALSO
NOW APPEARS THE CHANCE OF SHOWERS WILL ARRIVE SOONER...PERHAPS AS
EARLY AS LATE WEDNESDAY BUT CERTAINLY WEDNESDAY NIGHT INTO
THURSDAY. WARMING TEMPS DURING THIS PERIOD WITH SOUTHERLY FLOW
SHOULD KEEP PRECIP MAINLY LIQUID. A COLD FRONT THEN MOVES SOUTH
THURSDAY NIGHT AND FRIDAY WITH THE ECMWF MUCH COLDER THAN THE GFS
AND HAVE LOWERED TEMPS A FEW DEGREES DURING THIS TIME PERIOD AND
WHILE ITS STILL SEVERAL DAYS AWAY...POTENTIAL FOR SOME FROZEN
PRECIP EXISTS LATER FRIDAY/FRIDAY NIGHT...DEPENDING ON SPEED OF
FRONT AND END TIME OF PRECIP. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR CIGS THIS AFTERNOON AND POTENTIALLY THROUGH TONIGHT.
* SHRA WITH GRADUALLY INCREASING CHANCES FOR THUNDER THROUGH
EARLY EVE.
* SOUTH WINDS GUSTING TO AROUND 30 KT AT TIMES THROUGH THIS
EVE...THEN TURNING SOUTHWEST AND BECOMING EVEN MORE GUSTY ON
SUNDAY AFTERNOON.
* LOW LEVEL WIND SHEAR POSSIBLE AS WINDS NEAR 1500 FT INCREASE TO
50 KT OR STRONGER.
* TSRA CHANCES INCREASING AROUND DAYBREAK WITH GUSTY SEVERE STORM
POTENTIAL THIS MORNING AND EARLY AFTERNOON.
//DISCUSSION...UPDATED 18Z...
INITIAL LOW PRESSURE MOVING NORTHWARD INTO MN CONTINUES TO
INCREASE SOUTHERLY WINDS ACROSS THE AREA...AND AS AN EVEN MORE
POTENT LOW PRESSURE DEVELOPS ON SUNDAY THE SOUTH WINDS WILL REALLY
RAMP UP. SOUTHERLY GUSTS TO 30 KT OR EVEN SLIGHTLY HIGHER MAY BE
SEEN THIS AFTERNOON. SHOWERS WITH EMBEDDED SCATTERED THUNDER WILL
INCREASE IN COVERAGE THROUGH LATE AFTERNOON WITH THIS INITIAL LOW
PRESSURE. THERE PROBABLY WILL BE A SLIGHT DIMINISHING IN COVERAGE
THEN THROUGH THE MID TO LATE EVE AS THIS INITIAL MOISTURE SURGE
PASSES. BUT AS INFLUENCE OF THE SECOND WEATHER SYSTEM BEGINS TO
OVERSPREAD THE AREA...SCATTERED STORMS ARE LIKELY TO DEVELOP
OVERNIGHT INTO SUNDAY MORNING THAT WILL ADVANCING NORTHWARD.
THUNDER POTENTIAL WILL MAXIMIZE DURING THE LATE MORNING THROUGH
MID AFTERNOON FOR THE CHICAGO AREA TAF SITES. SOME OF THESE COULD
BE SEVERE GIVEN THE POTENT WIND FIELD AND SURPRISING INSTABILITY
WITHIN THIS SYSTEM FOR THIS TIME OF YEAR. WINDS AROUND AND UNDER
THESE STORMS WILL BE ESPECIALLY GUSTY...BUT EVEN THE PREVAILING
WINDS WILL BE VERY GUSTY BY AFTERNOON...WITH GUSTS OF 35KT+.
MTF
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE IN IFR CIGS THROUGH EARLY EVE.
* HIGH CONFIDENCE IN SHRA THROUGH EARLY THIS EVE.
* HIGH CONFIDENCE IN WIND DIRECTION...SPEEDS...AND GUSTS THROUGH
18Z SUNDAY...MEDIUM CONFIDENCE AFTER.
* HIGH CONFIDENCE IN 50-60KT SW WINDS IN THE 1500-3000FT LAYER
THIS EVE.
* MEDIUM CONFIDENCE IN TSRA TIMING THROUGHOUT THE TAF. HIGH
CONFIDENCE THAT IF STRONG TO SEVERE STORMS OCCUR AT THE AIRPORTS
THEY WOULD BE BE AFTER 10Z...AND MOST PROBABLE 17Z-21Z.
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...BREEZY WEST WINDS DIMINISHING LATE.
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...SLIGHT CHANCE SHRA DURING THE DAY AND RASN
AT NIGHT. MAINLY VFR.
MDB
&&
.MARINE...
354 AM CST
GALES THROUGH MONDAY AND A POTENTIAL PERIOD OF STORM FORCE WINDS
SUNDAY EVENING ARE THE FOCUS OF THIS FORECAST PERIOD. HIGH
PRESSURE REMAINS CENTERED OFF THE EAST COAST WITH EFFECTS OF THE
HIGH SPREAD BACK INTO THE EASTERN LAKES. LOW PRESSURE IS SPREAD
ACROSS THE PLAINS AND UPPER MIDWEST WITH CONSOLIDATION EXPECTED TO
OCCUR RESULTING IN A LOW TRACKING NORTHEAST TO WESTERN LAKE
SUPERIOR SUNDAY MORNING. THE PRESSURE GRADIENT WILL TIGHTEN AS
THIS LOW ORGANIZES ALLOWING SOUTH WINDS TO STEADILY INCREASE
ACROSS THE LAKE TODAY. WARMER AIR WILL BE MOVING INTO THE REGION
WHICH WILL CREATE SOME DEGREE OF A STABLE LAYER OVER THE LAKE
TODAY BUT GALES ARE STILL LIKELY TO DEVELOP THIS AFTERNOON AND
CONTINUE THIS EVENING. GALES WILL BE A BIT MORE MARGINAL IN THE
IL/IN NEARSHORE WATERS BUT OPTED TO HOIST A GALE WARNING FOR THESE
AREAS WITH 30 KT LIKELY AND DECENT POTENTIAL FOR GALE FORCE GUSTS
WITH QUITE A BIT OF WIND JUST ABOVE THE SURFACE...WITH BETTER
MIXING POSSIBLE THANKS TO AN OFFSHORE COMPONENT AT TIMES.
WINDS WILL EASE UP FOR A BRIEF PERIOD LATE TONIGHT AND EARLY
SUNDAY MORNING SO SPEEDS MAY FALL BELOW GALE FOR SEVERAL
HOURS...BUT WINDS WILL INCREASE AGAIN BY SUNDAY AFTERNOON AS A
STRONGER LOW EJECTS NORTHEAST FROM EASTERN COLORADO. THIS LOW WILL
RAPIDLY DEEPEN AS IT REACHES WISCONSIN AND THE EASTERN U.P. OF
MICHIGAN BY SUNDAY EVENING. MUCH WARMER AIR WILL BE DRAWN
NORTHWARD ACROSS THE LAKE BUT THE GRADIENT WILL BE TIGHT ENOUGH TO
SUPPORT GALES...EVEN IF MIXING IS VERY SHALLOW OVER THE COLDER
LAKE WATER. NEARSHORE AREAS MAY SEE THE STRONGEST WINDS DURING THE
DAY SUNDAY AS THE FLOW TURNS SOUTHWESTERLY AND WELL MIXED AIR
MOVES OFFSHORE. A FURTHER SHIFT TO WESTERLY WINDS WILL OCCUR AS
THE LOW FURTHER DEEPENS AND CONTINUES NORTHEAST DRAGGING A SHARP
COLD FRONT ACROSS THE LAKE BY SUNDAY EVENING. WITH THE DEEPENING
LOW AND UNSTABLE CONDITIONS DEVELOPING WINDS SHOULD INCREASE TO 45
KT WITH A DECENT POTENTIAL FOR 50 KT STORM FORCE WINDS SUNDAY
EVENING AND EARLY SUNDAY NIGHT. HAVE DECIDED TO EXTEND THE GALE
WARNING FROM LATE TONIGHT THROUGH MONDAY AFTERNOON AND EXPAND INTO
THE NEARSHORE WATERS...WITH AN EARLIER END TIME. WILL NEED TO KEEP
AN EYE ON THE DURATION OF ANY LULL PERIOD EARLY SUNDAY WHICH MAY
ALLOW FOR A SHORT WINDOW WITHOUT A GALE BUT AT THIS POINT THE
WINDOW LOOKS RATHER SHORT...ON THE ORDER OF 6-9 HOURS. STILL DO
HAVE SOME UNCERTAINTY ON THE TRACK OF THE LOW...WHETHER IT CROSSES
THE NORTHERN PART OF THE LAKE OR REMAINS JUST TO THE WEST AND
NORTH. RIGHT NOW PREFER THE WESTERN TRACK WHICH WOULD PROVIDE A
CLEANER SOUTHWEST TO WEST SHIFT OF THE WINDS AS OPPOSED THE
EASTERLY TRACK WHICH WOULD RESULT IN A BRIEF PERIOD OF NORTHERLY
WINDS OVER THE NORTHERN SECTIONS OF THE LAKE. WILL NEED TO KEEP AN
EYE ON THIS.
OTHERWISE WINDS WILL SLOWLY DIMINISH MONDAY AS HIGH PRESSURE
PASSES TO THE SOUTH AND EAST OF THE LAKE. LOW PRESSURE IS THEN
EXPECTED TO CROSS THE CANADIAN PRAIRIES TO JAMES BAY DURING THE
MIDDLE OF NEXT WEEK BRINGING ANOTHER INCREASE IN SOUTH WINDS WHICH
WILL FLIP NORTHWEST WITH A COLD FRONTAL PASSAGE LATER THURSDAY.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL NOON SATURDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 4
AM MONDAY.
GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
341 PM EST SAT NOV 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE
UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST
THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR
PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND.
FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A
SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE
NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND
EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO
SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER
LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE
HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER
THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN
UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED
AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL
BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION
TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS
IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING
AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN.
THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE
ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH
THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO
BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD
MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY
THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH
FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE
CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY
AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE
FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL
CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST
HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE
A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT
VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE
EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED
THUNDERSTORMS.
AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND
SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA
LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z
SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR
TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH
POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST
FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS
REASONABLE) AND ONLY MADE MINOR TWEAKS.
ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY
AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING
TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP
MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO
DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP
WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS).
DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS
EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A
STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE
HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY
WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS
LOWER LEVEL AIR SLIDES IN.
FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND
TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER
THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE
INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT
WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE
20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL
TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES
NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN
TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING
AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 521 AM EST SAT NOV 16 2013
LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE
UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG
WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A
TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT
MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A
SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK
RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN
INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS
AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER
WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY
PROBABLY LIGHT LES OFF LAKE SUPERIOR.
BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT
ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY
DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB
HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO
THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES
DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH
WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH
A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND.
IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND
E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE
CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE
SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW.
INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT
OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA
OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN
PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE
LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST.
WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A
MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA...
GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING
IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W
TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL
FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY
DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS.
BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD
DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST
SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL
SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T
APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL
IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL
PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN
LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY.
AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER
THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS
SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE
PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO
AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT
LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT
SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE
MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION
ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO
GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO
SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY
THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL.
LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW
ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO
SNOW ARE WARRANTED AT THIS TIME.
WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE
DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB
DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL
TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT
ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL
ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE
WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED
FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR...
HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT
POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT
INTO MON MORNING.
TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS
850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END
OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS
AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE
REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS
CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE
GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT
THESE COLDER NUMBERS.
WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG
SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT
ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET
UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE
INTENSITY OF THE COLD FOLLOWING THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EST SAT NOV 16 2013
ON FAVORABLE S WINDS WITH APPROACHING LOW LEVEL MOISTURE...CEILINGS
AT SAW QUICKLY FELL INTO THE IFR CATEGORY ...WHERE THEY WILL PRETTY
MUCH STAY /IFR TO LIFR/ THROUGH SUNDAY MORNING. AT THE OTHER
SITES...THE LOWER CLOUDS HAVE BEEN SLOWER TO ARRIVE...WITH IFR OR
MVFR CEILINGS EXPECTED TO SET IN THROUGH 09Z SUNDAY. SAW IS CLOSE TO
LLWS CRITERIA FROM 23Z SATURDAY THROUGH 06Z SUNDAY. HOWEVER...WITH
SFC WINDS STAYING UP WITH GUSTS ON THE ORDER OF 20-25KTS...WILL
EXCLUDE THE MENTION OF LLWS AT THIS TIME. RAIN WILL BE THE MAIN
WEATHER TYPE. LOOKING FARTHER AHEAD...EXPECT STRONG NW WINDS TO PUSH
IN BEHIND THE EXITING SFC LOW AFTER 00Z MONDAY. THE STRONGEST WINDS
WITH GUSTS NEAR 30KTS AT CMX AND TO A LESS EXTENT SAW...CONTINUING
THROUGH MID MORNING MONDAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 340 PM EST SAT NOV 16 2013
GALE AND STORM FORCE WIND WATCHES REMAIN IN PLACE FOR MUCH OF LAKE
SUPERIOR FOR LATE SUNDAY EVENING THROUGH MONDAY MORNING.
LOW PRESSURE OVER SOUTHERN MINNESOTA WILL SWING ACROSS
WESTERN LAKE SUPERIOR SUNDAY MORNING...WHILE AN ADDITIONAL LOW TO
THE SOUTH NEARS FROM THE SOUTHWEST. EXPECT THE LOWS TO COMBINE AND
DEEPEN SIGNIFICANTLY ACROSS FAR EASTERN LAKE SUPERIOR BY LATE SUNDAY
AFTERNOON...BEFORE EXITING NORTHEASTWARD TO JUST EAST OF JAMES BAY
MONDAY AFTERNOON. NW GALE TO STORM FORCE REMAIN POSSIBLE OVER MUCH
OF LAKE SUPERIOR LATE SUNDAY EVENING THROUGH MONDAY MORNING...WITH
GALES EXTENDING THROUGH EARLY MONDAY EVENING ACROSS THE E HALF OF
LAKE SUPERIOR.
HIGH PRESSURE STRETCHING FROM CENTRAL CANADA THROUGH THE SOUTHERN
PLAINS MONDAY WILL SLIDE ACROSS THE UPPER GREAT LAKES MONDAY NIGHT
AND TUESDAY. BEHIND THE EXITING HIGH...LOW PRESSURE ALONG THE
WESTERN U.S. AND CANADIAN BORDER ON TUESDAY WILL CROSS LAKE WINNIPEG
TUESDAY NIGHT INCHES...AND EXIT NORTHEAST ACROSS HUDSON BAY
WEDNESDAY INTO WEDNESDAY NIGHT WHILE DRAGGING A TROUGH ACROSS LAKE
SUPERIOR. EXPECT STRONG HIGH PRESSURE ACROSS THE PLAINS STATES
THURSDAY MORNING TO BUILD ACROSS THE UPPER GREAT LAKES BY THURSDAY
NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
HIGH WIND WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
MIZ001-006-007.
LAKE SUPERIOR...
STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ244-245-248>251-264>267.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ241>243-263.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LMZ221-
248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
123 PM EST SAT NOV 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTHWESTERLY FLOW IS BEGINNING TO INCREASE OVER THE CWA AS THE
UPPER TROUGH AMPLIFIES DUE TO A STRONG SHORTWAVE MOVING SOUTHEAST
THROUGH THE PACIFIC NORTHWEST. THIS SHORTWAVE WILL BE THE MAJOR
PLAYER TO OUR WEATHER FOR THE SECOND HALF OF THE WEEKEND.
FOR THE SHORT TERM...THE SOUTHWESTERLY FLOW ALOFT WILL ALLOW A
SHORTWAVE CURRENTLY LOCATED NEAR THE FOUR CORNERS REGION TO MOVE
NORTHEAST ACROSS THE UPPER GREAT LAKES LATE THIS AFTERNOON AND
EVENING. MOISTURE STREAMING NORTHEAST ON WV IMAGERY IS LEADING TO
SOME HIGH CLOUDS OVER MUCH OF UPPER MICHIGAN. IN THE LOWER
LEVELS...INITIAL RAP SOUNDINGS SHOWING PLENTY OF DRY AIR BELOW THE
HIGH CLOUDS BUT THERE WAS ENOUGH RADIATIONAL COOLING EARLIER
THIS EVENING TO PRODUCE SOME PATCHY FOG OVER CENTRAL/EASTERN
UPPER MICHIGAN. THE DRIER LOW LEVELS WILL LIKELY BE SHORT LIVED
AS 3-5KFT CEILINGS COVER MUCH OF CENTRAL/NORTHERN WISCONSIN AND WILL
BE MOVING INTO THE AREA OVER THE NEXT COUPLE OF HOURS. IN ADDITION
TO THOSE CLOUDS...MODELS ARE SHOWING THE DEVELOPING 1KFT CEILINGS
IN NORTHERN ILLINOIS TO QUICKLY LIFT NORTH AND EXPAND THIS MORNING
AND EARLY AFTERNOON...COVERING MUCH OF UPPER MICHIGAN.
THE SHORTWAVE WILL BE NEARING THE REGION THIS AFTERNOON AND THERE
ARE SEVERAL FEATURES SUPPORTING A BROAD AREA OF RAIN MOVING THROUGH
THE AREA LATE THIS AFTERNOON AND EVENING. FIRST...EXPECT THERE TO
BE A WEAK COUPLED JET STRUCTURE OVER THE AREA THIS EVENING. BROAD
MID LEVEL WARM AIR ADVECTION AND MOISTURE TRANSPORT WILL ACCOMPANY
THIS SHORTWAVE...WITH THE EASTERN CWA SEEING THE BEST OF BOTH
FEATURES. AT THE SURFACE...THE BROAD LOW DEVELOPING OVER THE
CENTRAL/NORTHERN PLAINS WILL SLIDE A TROUGH THROUGH MINNESOTA TODAY
AND OVER WESTERN LAKE SUPERIOR TONIGHT. HAVE HIGH CONFIDENCE IN THE
FORECAST FOR THIS AFTERNOON/EVENING BASED OFF GREAT MODEL
CONSISTENCY. SINCE THE BEST FORCING IS OVER THE SOUTHEAST
HALF...WILL HAVE THE HIGHEST POPS/QPF IN THAT AREA BUT THERE WILL BE
A PERIOD OF DEFINITE POPS OVER THE ENTIRE AREA. AS FOR QPF...EXPECT
VALUES TO RANGE FROM 0.2 OVER THE WEST TO 0.75IN OVER THE
EAST...WITH SOME HIGHER AMOUNTS IF THERE ARE SOME EMBEDDED
THUNDERSTORMS.
AS FOR THUNDER...THERE IS A POCKET OF 50-125J/KG OF MUCAPE AND
SHOWALTER VALUES SLIGHTLY BELOW 0 OVER THE EASTERN 2/3RDS OF THE CWA
LATE THIS AFTERNOON INTO THE EVENING HOURS. BOTH 00Z NAM AND 21Z
SREF PROBABILITIES INDICATE THE POTENTIAL FOR A RUMBLE OF THUNDER OR
TWO OVER THE SOUTHEAST PART OF THE CWA...WHICH CORRELATES WELL WITH
POCKET OF STEEPER 850-500MB LAPSE RATES MOVING THROUGH AND BEST
FORCING. PREVIOUS SHIFT HAD A SLIGHT CHANCE MENTIONED (WHICH SEEMS
REASONABLE) AND ONLY MADE MINOR TWEAKS.
ALL OF THE FORCING FEATURES WILL SHIFT NORTHEAST AROUND OR SHORTLY
AFTER MIDNIGHT (AND MID LEVEL DRYING OCCURS)...SO HAVE A DIMINISHING
TREND TO THE POPS FROM SOUTHWEST TO NORTHEAST. WITH THE DEEP
MOISTURE DEPARTING...DID TRANSITION THE PRECIP WORDING FROM RAIN TO
DRIZZLE OVERNIGHT (MAINLY OVER THE EASTERN AREAS). MODELS MATCH UP
WITH THAT IDEA (BLOTCHY LOOK TO QPF IN THE HIGHER RESOLUTION RUNS).
DID CONTINUE TO MENTION SOME FOG WITH THE RAIN THIS
EVENING...ALTHOUGH THE WIND MIGHT HELP KEEP IT MORE OF A
STRATUS WITH ONLY A SLIGHT LOWERING OF VISIBILITIES EXCEPT OVER THE
HIGHER TERRAIN. THUS...HAVE KEPT MOST OF THE AREA UNDER PATCHY
WORDING...ALTHOUGH DID IT DIMINISH OVER THE WEST OVERNIGHT AS
LOWER LEVEL AIR SLIDES IN.
FINALLY...WILL SEE INCREASING SOUTHERLY WINDS TODAY WITH A
TIGHTENING PRESSURE GRADIENT BETWEEN THE HIGH OFF THE EAST COAST AND
TROUGH MOVING EAST THROUGH MINNESOTA. STRONGEST WINDS WILL BE OVER
THE EASTERN CWA...WHERE THE LOW LEVEL JET WILL BE LOCATED. WITH THE
INCREASING LOW LEVEL MOISTURE AND EXPECTED CLOUD COVER...THINK THAT
WILL LIMIT MIXING AND KEEP WINDS IN CHECK (OCCASIONAL GUSTS IN THE
20-30MPH RANGE SEEN ON BUFKIT MOMENTUM TRANSFER). ABOVE NORMAL
TEMPERATURES WILL CONTINUE TODAY AND TONIGHT AS WARM AIR SLIDES
NORTH OVER THE AREA. THIS WARM AIR WILL REALLY SURGE IN
TONIGHT...WHICH COULD CAUSE MOST LOWS TO OCCUR EARLY THIS EVENING
AND THEN RISING OVERNIGHT INTO THE UPPER 40S AND AROUND 50.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 521 AM EST SAT NOV 16 2013
LONG TERM WILL START WITH A STRONG STORM SYSTEM LIFTING THRU THE
UPPER GREAT LAKES...BRINGING RAIN AND THEN A TRANSITION TO STRONG
WINDS...SNOW SHOWERS AND SEASONABLY COLD AIR. IT STILL LOOKS LIKE A
TREND TO LESS AMPLIFIED FLOW TOWARD THE MIDDLE OF NEXT WEEK. THAT
MAY ONLY BE SHORT-LIVED AS MEDIUM RANGE GUIDANCE IS NOW INDICATING A
SHARPER PROGRESSIVE TROF MOVING ACROSS THE NRN CONUS MID/LATE WEEK
RATHER THAN TROF REMAINING MORE CONFINED TO CANADA THAT HAD BEEN
INDICATED IN RECENT DAYS MODEL RUNS. END RESULT IS MODERATING TEMPS
AND A DRIER PATTERN HEADING INTO MID WEEK AND THEN A TURN TO COLDER
WEATHER LATE WEEK...ACCOMPANIED BY SOME -SHSN AND FOLLOWED BY
PROBABLY LIGHT LES OFF LAKE SUPERIOR.
BEGINNING SUN...ATTENTION WILL BE ON A STRONG SHORTWAVE SWINGING OUT
ACROSS THE CNTRL PLAINS. WAVE WILL GO NEGATIVE TILT AND RAPIDLY
DEEPEN AS IT PASSES ACROSS THE GREAT LAKES SUN NIGHT. 12HR 500MB
HEIGHT FALLS ARE STILL FCST TO MAX OUT AROUND AN IMPRESSIVE 280M TO
THE NE AND E OF GEORGIAN BAY. MAJORITY OF GUIDANCE STILL INDICATES
DEEPENING SFC LOW LIFTING NE THRU WI AND SE LAKE SUPERIOR...WHICH
WAS THE PREFERRED TRACK 24HRS AGO. THE GFS IS STILL THE OUTLIER WITH
A FARTHER E TRACK...PASSING ACROSS THE STRAITS AND DRUMMOND ISLAND.
IF ANYTHING...THE GFS HAS BEEN TRENDING VERY SLIGHTLY FARTHER S AND
E WITH THE TRACK IN RECENT RUNS. WILL CONTINUE TO USE THE MORE
CLIMATOLOGICALLY FAVORED SFC LOW TRACK ACROSS FAR SE LAKE
SUPERIOR...REPRESENTED BY THE ECMWF/UKMET/GEM AND 4KM NAM WINDOW.
INCREASING HEIGHT FALLS AND STRONG UPPER DIFFLUENCE WITH LEFT EXIT
OF 130KT UPPER JET NOSING INTO THE GREAT LAKES WILL SUPPORT AN AREA
OF SHRA SPREADING N INTO UPPER MI SUN AFTN...WITH THE HEAVIEST PCPN
PROBABLY SLIDING THRU CNTRL/ERN UPPER MI LATE AFTN/EVENING WHERE
LOW/MID LEVEL FRONTOGENESIS AND ISENTROPIC ASCENT ARE STRONGEST.
WITH SHOWALTER INDEX FALLING TO SLIGHTLY NEGATIVE...WILL CONTINUE A
MENTION OF THUNDER OVER ROUGHLY THE E HALF OF THE FCST AREA...
GENERALLY ALONG AND E OF EXPECTED SFC LOW TRACK. COLDER AIR WRAPPING
IN BEHIND THE SYSTEM WILL CHANGE RAIN TO SNOW RATHER QUICKLY FROM W
TO E DURING SUN NIGHT PER CONSENSUS OF MODEL THERMAL
FIELDS/SOUNDINGS. POTENTIAL FOR HVY SNOW OR EVEN MDT SNOW IS NOTABLY
DIMINISHED FROM WHAT SOME MODEL RUNS SUGGESTED IN RECENT DAYS.
BIGGEST PROBLEM IS TIMING OF HOW FAST DEFORMATION PCPN SHIELD
DEVELOPS/EXPANDS/ORGANIZES ON NW/W SIDE OF SYSTEM. WITH THE FAST
SPEED OF SHORTWAVE THRU THE WRN GREAT LAKES AND WITH SFC/MID LEVEL
SYSTEM NOT BECOMING WELL DEVELOPED UNTIL NE OF THE AREA...IT DOESN`T
APPEAR THE SYNOPTIC SNOW SHIELD WILL BECOME REALLY ORGANIZED UNTIL
IT MOVES INTO NRN ONTARIO TO THE N AND NE OF LAKE SUPERIOR. IT WILL
PROBABLY TURN INTO A FAIRLY SUBSTANTIAL SNOW STORM FOR AREAS BTWN
LAKE SUPERIOR AND JAMES BAY...ESPECIALLY TOWARD JAMES BAY.
AS IT APPEARS NOW...THE STEADIER/HEAVIER PCPN IN THE EVENING OVER
THE W WILL PROBABLY FALL MOSTLY AS RAIN. BY THE TIME COLUMN COOLS
SUFFICIENTLY FOR A CHANGEOVER TO SNOW...THE SYNOPTIC PCPN WILL BE
PULLING OUT. STILL...WITH CYCLONIC FLOW/850MB TEMPS FALLING TO
AROUND -9C BY 12Z MON AND DEEPER MOISTURE HANGING AROUND...EXPECT
LAKE ENHANCED SNOW TO DEVELOP OFF WRN LAKE SUPERIOR OVERNIGHT. MIGHT
SEE A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF THE W BY SUNRISE
MON...BUT WITH DENDRITIC SNOW GROWTH TEMPS ABOVE THE UPWARD MOTION
ZONE AND POTENTIALLY EVEN ABOVE THE MOIST LAYER...IT MAY BE TOUGH TO
GET A FEW INCHES OF SNOW. STRONG BOUNDARY LAYER WINDS SHOULD TEND TO
SPREAD THE LAKE ENHANCED SNOW A BIT FARTHER INLAND THAN IS USUALLY
THE CASE. HURON MTNS MAY BE AN AREA TO SEE MOST PERISTENT SNOWFALL.
LATE CHANGEOVER TO SNOW OVER THE E WILL FURTHER LIMIT SNOW
ACCUMULATIONS IN THAT AREA SUN NIGHT. NO HEADLINES PERTAINING TO
SNOW ARE WARRANTED AT THIS TIME.
WINDS WILL BE A BIG STORY WITH THE SYSTEM. IN THE WAKE OF THE
DEEPENING SFC LOW...MODELS INDICATE NW WINDS OF 45-55KT AT 850MB
DURING THE PERIOD OF CAA. 4KM HIGH RES NAM SHOWS WIND GUST POTENTIAL
TO A LITTLE OVER 40KT OVER THE KEWEENAW AND TO A LITTLE OVER 50KT
ALONG THE LAKESHORE E OF MARQUETTE. ISALLOBARIC WIND COMPONENT WILL
ADD SOME ENHANCEMENT AS PRES RISES STRENGTHEN OVER THE AREA IN THE
WAKE OF THE DEEPENING LOW. IF ADVY HEADLINES END UP NOT BEING NEEDED
FOR SNOWFALL...WIND HEADLINES WILL BE NEEDED. ON LAKE SUPERIOR...
HIGH GALES ARE LIKELY ON THE E HALF OF LAKE SUPERIOR WITH DECENT
POTENTIAL FOR A PERIOD OF STORM FORCE WINDS LATE OVERNIGHT SUN NIGHT
INTO MON MORNING.
TRANSITION TO PURE LES WILL OCCUR MON/MON NIGHT UNDER NW FLOW AS
850MB TEMPS FALL TO -10/-11C. LINGERING LIGHT LES WILL WIND DOWN/END
OVER WRN UPPER MI MON NIGHT AND OVER NCNTRL UPPER MI TUE MORNING AS
AS FLOW BACKS AND WAA GETS UNDERWAY. WITH SFC HIGH PRES RIDGE
REACHING WRN UPPER MI LATE MON NIGHT...TEMPS COULD PLUMMET IF CLOUDS
CLEAR OUT. NONE OF THE GUIDANCE IS ESPECIALLY COLD. LOWEST GUIDANCE
GENERALLY SUGGEST MINS IN THE UPPER TEENS...AND FCST WILL REFLECT
THESE COLDER NUMBERS.
WAA WED MIGHT YIELD SOME LIGHT PCPN AT THAT TIME. THEN...STRONG
SHORTWAVE MOVING ACROSS SRN CANADA WILL SWEEP ASSOCIATED COLD FRONT
ACROSS THE AREA WED NIGHT...ACCOMPANIED BY SOME -RA/-SN. LES MAY GET
UNDERWAY THU...BUT MODELS HAVE NOT BEEN VERY CONSISTENT ON THE
INTENSITY OF THE COLD FOLLOWING THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 121 PM EST SAT NOV 16 2013
ON FAVORABLE S WINDS WITH APPROACHING LOW LEVEL MOISTURE...CEILINGS
AT SAW QUICKLY FELL INTO THE IFR CATEGORY ...WHERE THEY WILL PRETTY
MUCH STAY /IFR TO LIFR/ THROUGH SUNDAY MORNING. AT THE OTHER
SITES...THE LOWER CLOUDS HAVE BEEN SLOWER TO ARRIVE...WITH IFR OR
MVFR CEILINGS EXPECTED TO SET IN THROUGH 09Z SUNDAY. SAW IS CLOSE TO
LLWS CRITERIA FROM 23Z SATURDAY THROUGH 06Z SUNDAY. HOWEVER...WITH
SFC WINDS STAYING UP WITH GUSTS ON THE ORDER OF 20-25KTS...WILL
EXCLUDE THE MENTION OF LLWS AT THIS TIME. RAIN WILL BE THE MAIN
WEATHER TYPE. LOOKING FARTHER AHEAD...EXPECT STRONG NW WINDS TO PUSH
IN BEHIND THE EXITING SFC LOW AFTER 00Z MONDAY. THE STRONGEST WINDS
WITH GUSTS NEAR 30KTS AT CMX AND TO A LESS EXTENT SAW...CONTINUING
THROUGH MID MORNING MONDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EST SAT NOV 16 2013
SOUTH WINDS WILL INCREASE TO 30KT TODAY AHEAD OF DEEPENING SFC LOW
MOVING FROM THE PLAINS TOWARD THE UPPER MISSISSIPPI VALLEY.
STRONGEST WINDS TODAY/TONIGHT WILL BE OVER EASTERN PORTIONS OF LAKE
SUPERIOR...WHERE THERE MAY BE A FEW GALE GUSTS TO 35KT. STABLE
LOW-LEVEL TEMPERATURE PROFILE AND LACK OF PRESSURE FALLS TO NORTH OF
LAKE SUPERIOR SHOULD LIMIT FREQUENCY OF GUSTS. WINDS WILL DIMINISH
FOR A TIME SUNDAY AS SFC TROF DRIFTS OVERHEAD AND PRES GRADIENT
WEAKENS CONSIDERABLY. NEW LOW PRESSURE ORGANIZING OVER THE PLAINS
WILL THEN LIFT NE ALONG THE TROF AND RAPIDLY DEEPEN AS IT PASSES
ACROSS FAR SE LAKE SUPERIOR INTO NRN ONTARIO. PRES WILL LIKELY FALL
BLO 975MB OR 29.0 INCHES AS IT MOVES N OF THE LAKE SUNDAY NIGHT/MON
MORNING. IN THE NW FLOW IN THE WAKE OF THE DEEPENING LOW PRES...
GALES WILL OCCUR ACROSS ALL BUT FAR WRN LAKE SUPERIOR WITH HIGH END
GALES TO STORM FORCE WINDS LIKELY SUN NIGHT/MON MORNING OVER THE E
HALF. GIVEN STORM POTENTIAL...A STORM WATCH HAS BEEN ISSUED FOR THE
E HALF OF LAKE SUPERIOR. WINDS WILL DIMINISH BELOW 30KT FROM W TO E
MON NIGHT...AND A PERIOD OF LIGHT WINDS UNDER 15KT SHOULD OCCUR TUE
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR. S WINDS WILL THEN
RAMP UP TO 20-30KT FOR WED BEHIND THE HIGH AND AHEAD OF THE NEXT
APPROACHING LOW PRES TROF.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ248>251-265>267.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ241>245-263-264.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR LMZ221-
248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...KF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
322 PM CST SAT NOV 16 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 240 PM CST SAT NOV 16 2013
FIRST WAVE OF -RA/-DZ...AND EVEN A FEW THUNDERSTORMS THAT DEVELOPED
ALONG THE LEADING EDGE OF THE STRONG VERTICAL LIFT ACROSS EC/SC MN
EARLIER THIS AFTN. VISIBLE SATELLITE IMAGERY THIS AFTN INDICATED THE
DRIER AIR MOVING ACROSS NW IOWA WHICH WILL IMPACT FAR SOUTHERN MN
THIS EVENING. SOME BREAKS IN THE CLD CVR ARE LIKELY WITH THIS AREA
OF DRIER AIR...BUT HOW FAR NORTH THIS CLEARING DEVELOPS REMAINS
UNCERTAIN. LATEST RAP HAS AREAS SOUTH OF HWY 212 REMAINING NEARLY
SATURATED BLW 2K THRU TONIGHT.
DEEP SFC LOW IN NE SD WILL SLOWLY MOVE ENE ACROSS CENTRAL MN THIS
EVENING...AND THEN ACROSS NE MN BY SUNDAY MORNING. THIS WILL KEEP
MOST OF CENTRAL MN IN A WEAK FLOW IN THE BOUNDARY LAYER AND
THEREFORE KEEPING LOW CLDS/FOG AND OCCASIONAL DRIZZLE IN THE
FORECAST. NEXT SHRTWV OF INTEREST WILL IMPACT MAINLY THE SE CWA WITH
-RA SUNDAY MORNING...INTO THE EARLY AFTN. FURTHER TO THE NW...THERE
REMAINS ENOUGH ENERGY TO KEEP LOW POPS OVERNIGHT...BUT WITH CAA ANY
PRECIPITATION AMTS WILL REMAIN LIGHT. SOME -SN/FLURRIES ARE POSSIBLE
SUNDAY AFTN BEFORE ANY LEFTOVER PRECIPITATION ENDS ACROSS CENTRAL
MN...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN THIS FORECAST PACKAGE.
TEMPS MAY BE A BIT LOWER IN FAR SOUTHERN MN IF SKIES CLR. THE LOW
CLDS/FOG AND DRIZZLE WILL KEEP THE REST OF THE CWA WITH LITTLE TEMP
CHG UNTIL SUNDAY AS WINDS SHIFT TO THE W/NW AND BEGIN TO GUST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 240 PM CST SAT NOV 16 2013
DRIER AIR SHOULD FOLLOW THE FROPA QUICKLY SUNDAY NIGHT WITH
CLEARING SKIES INTO MONDAY. MODELS CONTINUE TO ADVERTISE A
SIDESWIPING OF THE TROUGH MONDAY BEFORE IMPRESSIVE RIDGING
RETURNS TUESDAY AND WEDNESDAY. INCREASED TEMPS A DEGREE OR TWO
MONDAY AND MONDAY NIGHT...BUT SEVERAL DEGREES TUESDAY AS 925 MB
TEMPS OF +4C TO +8C PUSH INTO THE CWA. MIXING TO THAT LEVEL WOULD
YIELD HIGHS IN THE MID/UPPER 50S OVER SOUTHERN MN AND UPPER 40S
OVER WRN WI. DID NOT QUITE GO THAT HIGH YET SINCE THIS IS A
RELATIVELY NEW MODEL TREND...BUT EACH OF THE LAST SEVERAL RUNS
HAVE BEEN GETTING PROGRESSIVELY WARMER.
MODEL CONSISTENCY HAS IMPROVED TODAY WITH A DRY COLD FRONT
PROGGED TO PUSH THROUGH LATE WEDNESDAY OR WEDNESDAY NIGHT. THERMAL
RIDGING IN ADVANCE OF THE FRONT WILL KEEP TEMPERATURES MILD
TUESDAY NIGHT AND WEDNESDAY. A 1040 MB HIGH WILL BUILD IN BEHIND
THE FRONT...BUT MODELS DIFFER A BIT WHERE THIS WILL TRACK WHICH
WILL DETERMINE THE DEGREE OF COLD AIR LATE NEXT WEEK.
AN INVERTED TROUGH PUSHING THROUGH THURSDAY NIGHT OR FRIDAY MAY
BRING A COATING OF SNOW TO THE REGION. INTRODUCED LOW POPS FOR NOW
DURING THIS PERIOD.
AN INTERESTING DEVELOPMENT HAS EMERGED ON THE 12Z ECMWF AND
CANADIAN FOR NEXT WEEKEND. FOLLOWING THE INVERTED TROUGH...A
PROLIFIC 1050-1055MB HIGH BUILDING INTO THE NORTHERN
ROCKIES/NORTHWESTERN PLAINS COULD BRING OUR FIRST SHOT AT VERY
COLD TEMPERATURES. HOWEVER...THE GFS AND FIM MAINTAIN A MUCH
MILDER SOLUTION WITH A WEAKER AND MORE PROGRESSIVE HIGH REMAINING
IN CANADA SO CANNOT TREND TOWARD EITHER SOLUTION YET.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM CST SAT NOV 16 2013
MPX TAFS STARTING OUT WITH IFR/LIFR CIGS/VSBYS WHICH MAY IMPROVE
SOME DURING THE AFTN WITH MIXING OF -RA...BUT STILL REMAINING BLW 1K.
HOWEVER...NOT UNTIL DRIER AIR ADVECTS FROM THE SW ACROSS IA/NE
WILL WE SEE ANY SIGNIFICANT IMPROVEMENTS. THE WORSE TIME FRAME WILL
OCCUR IN THE FIRST 3 HRS WITH SOME POSSIBILITY OF TSRA AT
KRWF/KEAU DUE TO INCREASING CONVECTION NOTED IN THESE AREAS.
ALTHOUGH KRWF/KRHN/KEAU MAY SEE CIGS LIFT DURING THE EVENING HRS
TO MVFR...NOT TOO OPTIMISTIC UNTIL WINDS SHIFT AND INCREASE FROM
THE SW. LOW CONFIDENCE ON MVFR CIGS DEVELOPING THIS AFTN/EVENING.
AFT 3-6Z...WENT WITH A MORE IFR/LIFR CIGS/VSBYS AT KAXN/KSTC DUE
TO WEAK SFC WINDS AND MIXING IN THE BOUNDARY LAYER...PLUS THE
ADDED MOISTURE FROM -RA/-DZ THIS AFTN. ELSEWHERE...WILL CONTINUE
WITH SOME IMPROVEMENT IN THE EVENING...BUT LOWER THE CIGS ONCE
AGAIN AFT 6Z...THEN INCREASE THE CIGS/VSBYS AFT 12-15Z. WINDS WILL
REMAIN FROM THE S/SE THIS AFTN...THEN MORE S/SW THIS
EVENING...BECOMING MORE W/NW BY SUNDAY MORNING/AFTN.
KMSP...
KEPT THE LOWER CIGS THRU THE AFTN AND EVENING WITH VSBYS LOWERING
TO 2SM IN -RA/-DZ AT TIMES. ALTHOUGH REGIONAL RADAR DOES NOT HAVE
ANYTHING WIDESPREAD...BELIEVE IN THE NEXT HR OR TWO...PRECIPITATION
WILL EXPAND WITH HEAVIER ACTIVITY POSSIBLE 19-21Z WHERE BOTH THE
BEST LIFT AND DEEPER MOISTURE RESIDES. MORE OF A DRIZZLE SCENARIO
AFT 21-22Z...WITH DRIER AIR ADVECTING FROM THE SW THIS EVENING.
KEPT CIGS IFR...BUT MVFR CIGS MAY DEVELOP DURING THE 02-04Z TIME
FRAME. MVFR/VFR CIGS CONTINUE THRU SUNDAY MORNING WITH VFR CONDS
DEVELOPING SUNDAY AFTN AS WINDS INCREASE FROM THE NW. CONFIDENCE
REMAINS HIGH FOR THE CONTINUED IFR CIGS THIS AFTN...CONFIDENCES
LOWERS WITH MVFR CIGS DEVELOPING THIS EVENING/OVERNIGHT.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS EARLY. THEN VFR. WINDS WNW AT 10G15KTS.
TUE...VFR. WINDS SE AT 10KTS.
WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...BORGHOFF
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS GLASGOW MT
349 PM MST SAT NOV 16 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
SHORT TERM MODEL SOLUTIONS CONTINUE TO BE OF VERY LITTLE HELP AND
SIGNIFICANT SNOW FALL AMOUNT AND PLACEMENT DISCREPANCIES ABOUND.
FORECAST CHALLENGES WILL FOCUS ON TRYING TO WORK OUT THESE TWO
PROBLEMS THROUGH SUNDAY.
OF MOST HELP WILL LIKELY BE COMPARING RADAR IMAGERY WITH MODEL
SOLUTIONS TO SEE WHICH ONE IS PERFORMING THE BEST AND TRY TO LEAN
WITH OR TRUST THAT ONE MORE THAN THE OTHERS. AT THE ONSET OF THIS
SYSTEM...THE HRRR MODEL SEEMS TO BE PERFORMING THE BEST.
ENOUGH ACCUMULATING SNOW SEEMS LIKELY TO SNEAK ACROSS THE
INTERNATIONAL BORDER TO ACCUMULATE AROUND 2 INCHES FOR OUR
NORTHEASTERN ZONES. WENT AHEAD AND ISSUED A WINTER WEATHER
ADVISORY FOR SHERIDAN AND EASTERN ROOSEVELT COUNTIES. MOST OTHER
LOCATIONS WILL PROBABLY RECEIVE AROUND 1 INCH OF SNOW.
ALTHOUGH SOME MODELS SHOWED POST-FRONTAL WINDS BELOW 15
KNOTS...ALL NEAR SHORT-TERM AND HIGH-RESOLUTION MODELS ARE IN
AGREEMENT SHOWING STRONG AND GUSTY WEST-NORTHWESTERLY WINDS
PUSHING INTO THE AREA AFTER MIDNIGHT TONIGHT. CHOSE TO ISSUE A
LAKE WIND ADVISORY FROM AFTER MIDNIGHT TONIGHT THROUGH THE DAY ON
SUNDAY.
BY SUNDAY NIGHT...THE LARGE UPPER-LEVEL TROUGH PIVOTS
EASTWARD...PARTIALLY CLEARING OUR SKIES AND DRIVING ANY
PRECIPITATION AWAY AS THE FLOW ALOFT TURNS MORE ZONAL.
AFTER A GOOD HARD FREEZE TONIGHT AND SUNDAY NIGHT...TEMPERATURES
WILL EASILY REBOUND TO MORE NORMAL VALUES FOR THIS TIME OF YEAR.
BMICKELSON
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
GOING FORECAST IS IN OVERALL GOOD SHAPE. MODELS CONTINUE TO AGREE
IN A SHORTWAVE PASSAGE LATE TUESDAY INTO WEDNESDAY. MODELS REMAIN
RELATIVELY DRY WITH THIS FEATURE...BUT WE CONSERVATIVELY TRENDED
UP POPS GIVEN DECENT CONSISTENCY.
MODEL DIFFERENCES ARE PRESENT FOR NEXT FRIDAY INTO SATURDAY. THE
GFS AND DGEX ARE WARMER...BUILDING IN WEAK RIDGING BEHIND THE
EXITING UPPER TROUGH. THE ECMWF AND GEM BOTH DROP ANOTHER UPPER
TROUGH THROUGH WITH ANOTHER BLAST OF ARCTIC AIR. CONTINUED TO
LEAN MORE ON THE SIDE OF THE COOLER ECMWF AND GEM DUE TO THEIR
RECENT BETTER PERFORMANCE...BUT REMAIN MUCH WARMER THEN THE
OPERATIONAL RUNS. GILCHRIST
PREVIOUS LONG TERM DISCUSSION...TUESDAY WILL BE MILD AND DRY WITH
ZONAL FLOW ALOFT. SHORTWAVE UPPER TROUGH MOVES THROUGH MONTANA ON
WEDNESDAY AND DRAGS A STRONG COLD FRONT SOUTH. THE SYSTEM HAS
LIMITED MOISTURE SO THAT THE ANY PRECIPITATION THAT OCCURS WILL BE
MAINLY ALONG THE FRONT. MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE TIMING OF THE FRONT BUT THE GFS TRACKS THE UPPER LEVEL
DYNAMICS ACROSS SASKATCHEWAN WHILE THE ECMWF TAKES IT ACROSS
MONTANA. WILL MENTION A SLIGHT CHANCE OF SNOW FOR NOW.
COLD HIGH PRESSURE BUILDS INTO AREA WEDNESDAY NIGHT AND PREVAILS
THROUGH FRIDAY WITH DRY WEATHER. NORTHWEST FLOW ALOFT WILL KEEP
TEMPERATURES ON THE COLD SIDE OF NORMAL. UPPER RIDGE BUILDS INTO
THE AREA BY NEXT WEEKEND WITH A WARMING TREND. FORRESTER
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON FOR ALL
TERMINALS. IN THE WAKE OF THE COLD FRONT THAT WILL PASS THROUGH
THIS EVENING WEST TO NORTHWEST WINDS WILL RAMP UP AFTER MIDNIGHT AND
MAINTAIN SPEEDS OF 15 TO 25KTS FROM ABOUT 9Z SUNDAY TO 00Z MONDAY.
CEILINGS... AND POSSIBLY VISIBILITY MAY DROP TO MVFR TONIGHT AS
RAIN AND SNOW SHOWERS MOVE OVER THE TERMINALS. BRIEF PERIODS OF
IFR CONDITIONS CAN NOT BE RULED OUT IF A MORE INTENSE BAND MOVES
THROUGH THE AREA. SNOW WILL TAPER OFF SUNDAY MORNING AND AFTERNOON
FOR ALL TERMINALS AS THE SYSTEM EXITS TO THE EAST. AEC
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 1 AM TO 5 PM MST SUNDAY FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR EASTERN
ROOSEVELT...SHERIDAN.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
106 PM CST SAT NOV 16 2013
.UPDATE...
ISSUED AT 107 PM CST SAT NOV 16 2013
LOW PRESSURE WILL REMAIN OVER THE AREA TODAY AS AN UPPER LEVEL
TROUGH DIGS FROM THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS.
MAIN EARLY AFTERNOON UPDATES WERE TO LOWER TEMPERATURES AS
EXTENSIVE CLOUD COVER AND LIGHT PRECIPITATION WILL LIMIT HEATING.
ALSO ADJUSTED POPS BASED ON LATEST RADAR IMAGERY.
UPDATE ISSUED AT 947 AM CST SAT NOV 16 2013
RADAR RETURNS CONTINUE OVER WESTERN AND NORTH CENTRAL NORTH DAKOTA
AND HAVE EXPANDED AREAL COVERAGE OF SLIGHT CHANCE POPS. ALSO ADDED
A SLIGHT CHANCE OF PRECIPITATION OVER THE FAR SOUTHEAST COUNTIES
AS RETURNS HAVE INCREASED HERE AS WELL OVER THE PAST FEW HOURS.
PRECIPITATION WILL BE RAIN IN THE SOUTHEAST WITH A RAIN SNOW MIX
NORTH AND WEST FOR ANOTHER HOUR OR TWO...BEFORE RAIN THIS
AFTERNOON. PRECIPITATION AMOUNTS TODAY WILL BE LIGHT. A FEW AREAS
OF SUN OVER THE FAR SOUTH CENTRAL YET THIS MORNING...BUT CLOUDS
WILL CONTINUE TO INCREASE DURING THE DAY. WILL TAKE A CLOSER LOOK
AT TEMPERATURES LATE MORNING/EARLY THIS AFTERNOON.
UPDATE ISSUED AT 629 AM CST SAT NOV 16 2013
EARLY MORNING RADAR MOSAIC SHOWS A FEW RETURNS ACROSS THE NORTHWEST
AND SOUTHEAST PARTS OF THE STATE. THE 12Z KBIS SOUNDING SHOWS
THERE IS QUITE A BIT OF DRY LOW LEVEL AIR TO OVERCOME...SO MAINLY
VIRGA IS EXPECTED OVER THE NEXT FEW HOURS. THE EXCEPTION WOULD BE
IN THE NORTHWEST WHERE THE LATEST RAP SUGGESTS THERE COULD BE
LIGHT PRECIPITATION THIS MORNING. ESTEVAN HAS REPORTED A FEW
FLURRIES IN THE PAST HOUR...SO WILL INCREASE THE COVERAGE OF THE
SLIGHT CHANCES POPS THIS MORNING TO FALL IN LINE CLOSER TO THE
COVERAGE SHOWN BY THE RAP. DO NOT EXPECT MUCH ACCUMULATION...THUS
KEPT POPS LOW.
UPDATED TEMPERATURES TO BETTER REFLECT CURRENT CONDITIONS...OTHERWISE
THE FORECAST LOOKS TO BE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 310 AM CST SAT NOV 16 2013
A WINTER WEATHER ADVISORY WILL NOT BE ISSUED FOR THIS EVENT...AT
LEAST NOT WITH THIS FORECAST CYCLE...BASED ON CURRENT EXPECTATIONS
OF JUST AN INCH OR TWO TOTAL SNOWFALL SATURDAY NIGHT THROUGH
SUNDAY. WE ARE DEEP ENOUGH NOW INTO THE SNOW SEASON WHERE AN
ADVISORY IS NOT JUSTIFIED. WE MAY OPT TO HIGHLIGHT THE EVENT
THROUGH A SPECIAL WEATHER STATEMENT AS SUNDAY WILL BE WINDY AND
MUCH COLDER.
TWO POINTS OF INTEREST FOR THE SHORT TERM. THE FIRST IS THE ABOVE
NORMAL TEMPERATURES FOR TODAY...SATURDAY. ENJOY IT IF YOU CAN AS
HIGH TEMPERATURES WILL BE 5 TO 10 DEGREES ABOVE MID NOVEMBER
NORMALS. COOLER THAN FRIDAY...BUT STILL ABOVE NORMAL. THE SECOND
POINT IS THE COLDER WEATHER MOVING IN FOR TONIGHT WITH RAIN
CHANGING TO SNOW.
FOR TODAY...SURFACE HIGH PRESSURE AND MID LEVEL RIDGING WILL SLIDE
/ SHIFT OFF TO THE EAST AS AN OPEN MID LEVEL WAVE APPROACHES FROM
THE NORTHWEST. AHEAD OF THE SURFACE LOW...CLOUDS WERE ALREADY
ADVANCING INTO THE WESTERN PART OF THE FORECAST AREA...AND WILL
MAKE FOR A MOSTLY CLOUDY AFTERNOON ACROSS ALL OF THE FORECAST
AREA. A WEAK WARM FRONT SLIDING THROUGH LATER TODAY WILL PUSH
TEMPERATURES INTO THE 40S FOR HIGHS...AND BRING THE CHANCE FOR AN
ISOLATED RAIN SHOWER TO THE WEST.
FOR TONIGHT...LARGE SCALE LIFTING INCREASES AS THE MID LEVEL AND
SURFACE WAVE APPROACH. COOLING WILL BE DELAYED...AS WE WILL BE ON
THE SO CALLED WARM SIDE OF STORM...UNTIL AFTER 9 PM OR SO.
PRECIPITATION STARTS AS RAIN AND THEN TRANSITIONS TO SNOW AS THE
ATMOSPHERE COOLS. THE CHANGE TO SNOW OCCURS ALONG HIGHWAY 2 AROUND
9 PM CST...AND ALONG I-94 AROUND 11 PM OR MIDNIGHT CST. THE SNOW
THROUGH DAYBREAK SUNDAY WILL BE LIGHT IN INTENSITY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 310 AM CST SAT NOV 16 2013
SUNDAY WILL BEGIN WITH A LARGE TROUGH ACROSS THE CENTRAL UNITED
STATES WHICH HELPS PUSH ANOTHER COLD FRONT THROUGH THE NORTHERN
PLAINS. SHORT TERM MODELS HAVE COME INTO BETTER AGREEMENT
REGARDING PRECIPITATION CHANCES...AND SUGGEST HIGHER CHANCES FOR
SUNDAY MORNING. HAVE INCREASED POPS ACCORDINGLY AND NOW HAVE POPS
APPROACHING CATEGORICAL IN THE NORTHWEST.
IT APPEARS THE MAJORITY OF THE PRECIPITATION WILL FALL AS SNOW AS
COLDER AIR WORKS IT WAY INTO THE REGION. SNOW AMOUNTS SUNDAY SHOULD
GENERALLY STAY LESS THAN 1.5 INCHES. HIGH TEMPERATURES IN THE MID
20S TO MID 30S ON SUNDAY WILL BE MUCH COOLER THAN THOSE EXPECTED
FOR TODAY (SATURDAY). THE COLDER TEMPERATURES COMBINED WITH A
GUSTY NORTHWESTERLY WIND WILL MAKE FOR A RATHER BLUSTERY DAY.
SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT...AND WILL GO DRY
ACROSS THE FORECAST AREA. THAT BEING SAID...SOME MODEL SOLUTIONS DO
SUGGEST THE POSSIBILITY OF LINGERING LIGHT SNOW IN THE FAR EAST
EARLY SUNDAY EVENING...BUT DID NOT FEEL CONFIDENT ENOUGH TO ADD A
POP AT THE MOMENT.
H5 HEIGHTS RISE MONDAY WITH WARMER AIR RETURNING TO THE NORTHERN
PLAINS FOR EARLY NEXT WEEK. THE WARMER AIR DOES NOT STAY IN PLACE
FOR VERY LONG WITH ANOTHER COLD FRONT DROPPING ACROSS DAKOTAS
WEDNESDAY INTO WEDNESDAY NIGHT. THE FRONT WILL ALSO BRING ANOTHER
CHANCE OF PRECIPITATION...AGAIN MAINLY IN THE FORM OF SNOW. AT THE
MOMENT...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION
MAKER. DRIER WEATHER TAKES HOLD AGAIN FOR THURSDAY AND FRIDAY.
WARMER AIR RETURNS AGAIN FRIDAY INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 107 PM CST SAT NOV 16 2013
THIS AFTERNOON RAIN WILL IMPACT KISN AND KMOT...MOVING INTO
KDIK...KBIS...AND KJMS THROUGH THE EVENING. RAIN IS EXPECTED TO TURN
TO SNOW INTO THE OVERNIGHT HOURS. THERE IS SOME UNCERTAINTY AS TO
WHEN THE CHANGEOVER WILL OCCUR. DURING THE TAF PERIOD...EXPECT MVFR
CONDITIONS WITH LOWER CEILINGS AND REDUCED VISIBILITIES. WINDS WILL
GRADUALLY INCREASE THROUGH THE END OF THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JPM
LONG TERM...CK
AVIATION...AC
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1157 AM CST SAT NOV 16 2013
.UPDATE...
18Z AVIATION DISCUSSION UPDATED BELOW.
FOG IS STILL PRESENT ACROSS PARTS OF NORTHEAST SOUTH DAKOTA AND
WEST CENTRAL MINNESOTA. THE KATY OB HAS IMPROVED FROM A QUARTER
MILE VISIBILITY UP TO A HALF...BUT WITHOUT ANYTHING TO SCOUR OUT
THE LOW LEVEL MOISTURE...LEFT THE FOG MENTION IN THROUGH THE EARLY
AFTERNOON HOURS. A NARROW AREA OF SPRINKLES HAS DEVELOPED ALONG A
LINE FROM EUREKA TO BOWDLE TO HOVEN...SO ADDED THIS MENTION INTO
THE FORECAST...AND ADJUSTED THE TIMING OF POPS MOVING INTO
NORTHEAST SOUTH DAKOTA TO MATCH CURRENT RADAR TRENDS.
OTHERWISE...THE OVERALL FORECAST REMAINS ON TRACK THIS MORNING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA
EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE
SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST
THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID
LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO
WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER
SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST
SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT
TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF
PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO
SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW
PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS
STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW
CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH
DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY
GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL
THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY.
REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST
CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT
ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE
IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH
WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT
REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP
BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK.
ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY
MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS
CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE
INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE
DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT
PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD
THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN
BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE
MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS
HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS
TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST
UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST
CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER
MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT
THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY
WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD
BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY.
WILL CONTINUE TO MONITOR.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH
TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE
FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS
THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD
OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE
DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE
FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A
SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER
RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER
CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL.
THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION
BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW
WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT
FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW
ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG
BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12
HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES
STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS
STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH
OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS
POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE
EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW
MORNING...AS WELL.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
ONE UPPER LEVEL LOW PRESSURE SYSTEM WAS LEAVING THE EASTERN PART
OF THE REGION THIS AFTERNOON WHILE ANOTHER STRONGER SYSTEM WAS
MOVING IN FROM THE NORTHWEST. THE LOW STRATUS AND FOG AT ATY IS
EXPECTED TO BREAK UP/LIFT THROUGH THE AFTERNOON...POSSIBLY
REFORMING AGAIN TONIGHT. AT THIS TIME...LEFT IT OUT OF ATY FOR
TONIGHT AND WILL HAVE TO WATCH. OTHERWISE...AS THE MID AND HIGH
LEVEL CLOUDS EXIT WITH THE FIRST SYSTEM MORE VFR CLOUDS WILL
SPREAD IN WITH THE NEXT SYSTEM. SOME SCATTERED LIGHT RAIN SHOWERS
WILL ALSO SPREAD IN FOR LATER TONIGHT AND SUNDAY MORNING POSSIBLY
AFFECTING THE TERMINALS WITH NO REDUCTION IN VISIBILITY EXPECTED.
MAY HAVE TO INSERT IN TERMINALS AS WE GET CLOSER. NORTHWEST WINDS
ARE EXPECTED TO ALSO PICK UP ON SUNDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1041 AM CST SAT NOV 16 2013
.UPDATE...
FOG IS STILL PRESENT ACROSS PARTS OF NORTHEAST SOUTH DAKOTA AND
WEST CENTRAL MINNESOTA. THE KATY OB HAS IMPROVED FROM A QUARTER
MILE VISIBILITY UP TO A HALF...BUT WITHOUT ANYTHING TO SCOUR OUT
THE LOW LEVEL MOISTURE...LEFT THE FOG MENTION IN THROUGH THE EARLY
AFTERNOON HOURS. A NARROW AREA OF SPRINKLES HAS DEVELOPED ALONG A
LINE FROM EUREKA TO BOWDLE TO HOVEN...SO ADDED THIS MENTION INTO
THE FORECAST...AND ADJUSTED THE TIMING OF POPS MOVING INTO
NORTHEAST SOUTH DAKOTA TO MATCH CURRENT RADAR TRENDS.
OTHERWISE...THE OVERALL FORECAST REMAINS ON TRACK THIS MORNING.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
WEAK UPPER LEVEL DISTURBANCE DRIFTING NORTHEAST ACROSS THE AREA
EARLY THIS MORNING. WEAK LIFT SLIDING THROUGH AND FOG SATELLITE
SHOWING SOME TEXTURE TO THE MID LEVEL DECK MOVING NORTHEAST
THROUGH THE CWA. RADAR HAS SOME VERY LIGHT RETURNS WITHIN THE MID
LEVEL DECK......MAYBE JUST A COUPLE SPRINKLES. MAIN THING TO
WATCH TODAY IS THE SECONDARY WAVE WHICH IS A TAD FURTHER
SOUTH...AND ITS EXPECTED DEVELOPMENT OF SHOWERS ACROSS SOUTHEAST
SOUTH DAKOTA INTO MINNESOTA. EVEN THIS CLOSE TO EVENT
TIME...MODELS STILL HAVING A TOUGH TIME DETERMINING PLACEMENT OF
PRECIP AND THE HANDLING OF THE STRATUS DECK WELL TO THE SOUTH. NO
SIGN OF STRATUS ANYWHERE NEAR THE CWA...WITH THINGS RIGHT NOW
PUSHED WELL SOUTH INTO KANSAS AND MISSOURI. ALTHOUGH...MODELS
STILL SUGGESTING SOME DEVELOPMENT SHORTLY AFTER 12Z. VERY LOW
CONFIDENCE IN JUST HOW FAST STRATUS MAKES IT INTO SOUTHEAST SOUTH
DAKOTA AND THE SOUTHEAST CWA. FOR RIGHT NOW HAVE CONSTRUCTED SKY
GRIDS TO SHOW SOME INCREASE IN CLOUDS LATER THIS MORNING. FEEL
THERE WILL BE AT LEAST SOME DEVELOPMENT OF STRATUS BY LATER TODAY.
REMOVED DRIZZLE FROM THE FORECAST AS SOUNDINGS OVER THE SOUTHEAST
CWA JUST DO NOT SUPPORT IT. NO DEEP MOISTURE LAYER DOWN LOW AT
ALL. BETTER SIGNAL SHOWS UP CLOSE TO SIOUX FALLS AREA. WILL LEAVE
IN 20 POPS ACROSS THE FAR EASTERN CWA TO SORT OF GO ALONG WITH
WHAT THE HRRR AND ABR 4KM MODELS ARE SHOWING. AT THIS POINT...NOT
REALLY BUYING INTO THE MORE QPF-HAPPY EC AND GFS WHICH HAS PRECIP
BACK FURTHER WEST INTO THE JAMES VALLEY WITHIN A STRATUS DECK.
ATTENTION THEN TURNS TO THE STRONGER UPPER LEVEL SHORTWAVE ENERGY
MOVING ACROSS THE DAKOTAS LATE TONIGHT THROUGH SUNDAY. MODELS
CONTINUE TO WARM THE LOWER LEVELS OF THE ATMOSPHERE AND HAVE
INCREASED HIGHS ON SUNDAY. NOW IT APPEARS MOST OF TONIGHT WILL BE
DRY WITH CHANCES MOVING INTO THE WESTERN CWA BY 12Z SUNDAY. LEFT
PRECIP MOSTLY RAIN THOUGH AS THERMAL PROFILES STILL FAIRLY MILD
THROUGH THE NIGHT. AROUND 12Z SUNDAY AND SHORTLY AFTER THE COLUMN
BEGINS TO COOL ENOUGH TO SUPPORT MAINLY SNOWFALL DURING THE
MORNING HOURS...BUT WARMING AGAIN DURING THE AFTERNOON. MODELS
HAVING A TOUGH TIME WITH THIS SHORTWAVE ENERGY AS WELL IN REGARDS
TO PRECIP PLACEMENT. OVERALL...A FAIRLY LOW CONFIDENCE FORECAST
UNFORTUNATELY. BUT HAVING SAID THAT...IT DOES APPEAR THE BEST
CHANCE FOR PRECIP IN THE SHORT TERM WILL BE WITH WHATEVER
MATERIALIZES WITHIN THE UPPER LEVEL SHORTWAVE ENERGY LATER TONIGHT
THROUGH SUNDAY. ALSO NEED TO MENTION THE WINDS ON SUNDAY AS THEY
WILL GET RATHER GUSTY WITHIN A TIGHTENING PRESSURE GRADIENT. COULD
BE LOOKING AT WIND ADVISORY SPEEDS OVER THE WESTERN CWA ON SUNDAY.
WILL CONTINUE TO MONITOR.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
SEEMS THE GLOBAL SPECTRAL MODELS ARE CONTINUING TO HAVE A TOUGH
TIME RESOLVING FLOW PATTERN EVOLUTION AND SHORT-WAVE TIMING IN THE
FARTHER OUT FORECAST TIME PERIODS. FOR THE PAST COUPLE OF MORNINGS
THE GFS AND ECMWF HAVE BEEN HINTING AT THE DEVELOPMENT OF A PERIOD
OF SPLIT FLOW IN THE OUT PERIODS. MODELS ARE KNOWN TO HAVE
DIFFICULTIES RESOLVING FLOW PATTERN FEATURES IN THE SHORTER RANGE
FORECAST PERIODS /CONSIDERABLY LOWER FORECAST CONFIDENCE/ WHEN A
SPLIT FLOW PATTERN IS OCCURRING OR IMMINENT...LET ALONE THE LONGER
RANGE FORECAST TIME-FRAME. SO IT WOULD BE SAFE TO SAY...FORECASTER
CONFIDENCE IN LONGER RANGE SOLUTIONS IS LOWER THAN NORMAL.
THE ECMWF STILL HAS A STRONG COLD FRONT WORKING THROUGH THE REGION
BY THE MIDDLE OF NEXT WEEK. IT DOES NOT HAVE A BAND OF SNOW
WORKING ACROSS THE CWA...THOUGH...FOR WEDNESDAY NIGHT. THAT
FEATURE HAS SLOWED BY ABOUT 12 HOURS AND IS FURTHER SOUTH NOW
ACROSS NEBRASKA. THE GFS COLD FRONTAL FEATURE STILL SEEMS TO LAG
BEHIND THE ECMWF BY ABOUT 12 HOURS...WHILE THE GEM REMAINS APPX 12
HOURS FASTER THAN THE ECMWF. SO...WITH FRONTAL TIMING DIFFERENCES
STILL ABOUNDING...AND PRECIPITATION TIMING/PLACEMENT FORECASTS
STILL EVOLVING...SEEMS LIKE GOING AS DRY AS POSSIBLE FOR AS MUCH
OF THE LONG TERM AS POSSIBLE IS A GOOD MOVE THIS MORNING. AT THIS
POINT...THURSDAY STILL LOOKS LIKE THE COLDEST DAY OF THE
EXTENDED...ALTHOUGH THAT WILL PROBABLY CHANGE BY TOMORROW
MORNING...AS WELL.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR SHOULD PREVAIL TODAY AND TONIGHT AT KMBG...KPIR AND KABR.
THERE MAY BE A COUPLE SPRINKLES OR FLURRIES AT KPIR AND KABR AND
ALONG A LINE BETWEEN THESE TWO TERMINALS THROUGH ABOUT MID-DAY
TODAY. BUT...THIS SHOULD NOT IMPACT CIGS OR VISBIES.
KATY CONTINUES TO REMAIN THE CONCERN FOR SUB-VFR CONDITIONS.
SURFACE TO TOP-OF-THE-BOUNDARY-LAYER MOISTURE CONTINUES TO
INCREASE THIS MORNING ON LIGHT SOUTH WINDS. UPSTREAM FROM
KATY...SITES ACROSS SERN SOUTH DAKOTA AND SWRN MINNESOTA ARE
REPORTING IFR CIGS AND IN SOME CASES MVFR/IFR VISBIES. SEEMS
INCREASINGLY PROBABLE THAT KATY WILL BE DOWN INTO SOME FORM OF
SUB-VFR FLYING CONDITIONS WITHIN THE NEXT 3 TO 6 HOURS. THERE IS
ALSO A CHANCE FOR SOME RAIN AT KATY MAINLY LATER THIS AFTERNOON
FOR A FEW HOURS AS A LOW PRESSURE SYSTEM LIFTS NEWD ACROSS THE
REGION.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1015 AM PST Sat Nov 16 2013
.SYNOPSIS...
Low pressure will continue to bring rain and snow snow showers
across Inland Northwest today. Accumulating snow are expected
in the mountains, as well as some northern valley location. A
shower threat will linger into Sunday and early Monday. A much
wetter, but warmer system moves into the area late Monday. It
impacts will continue Tuesday and Wednesday.
&&
.DISCUSSION...
Morning update: low pressure/inverted surface trough will continue
to migrate across the region this morning and afternoon, weakening
as it does. This will keep scattered to locally numerous rain and
snow showers alive across the eastern third of WA/north ID. The
west to northwest flow will continue to focus some of the higher
snow amounts toward the ID mountains through tonight. Some brief
moderate to heavy snow showers will also be possible in some of
the heavier bands around the northeast WA mtns, the Blues and
Camas Prairie through this afternoon. Thus winter storm warnings
will continue through tonight over ID, while advisories will
linger over the northeast WA mtns, Blues and Camas Prairie through
afternoon...largely above about 2000 to 3500 feet.
I removed the advisory from the Okanogan Highlands, where shower
coverage is winding down to mainly isolated. I also let the
advisory around the COE zone expire; though some snow showers will
continue through the afternoon they will be mixed with rain as
temperatures are warming above freezing and this should limit the
amount of accumulation.
I did continue the winter weather advisory for the Cascade crest.
A look at webcams, especially around Stevens Pass, indicates some
unpleasant conditions. The HRRR also indicates some moderate bands
of snow continue in this region through at least this afternoon.
We will have to watch trends to see if this needs to be extended
longer. /J. Cote`
&&
.AVIATION...
18Z TAFS: low pressure over eastern WA/north ID will continue to
focus MVFR/lcl IFR cigs and vis with scattered rain and snow
showers around KGEG-KCOE and KPUW, especially before evening. A
period of VFR conditions is possible this afternoon, with breezy
conditions, before cigs drop toward MVFR/lcl IFR after 03-08Z
tonight through Sunday. A threat of showers will be also found
near KLWS through early evening. Toward Sunday morning a small
shower near KEAT as the next system approaches. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 27 41 31 42 35 / 20 10 40 40 30 60
Coeur d`Alene 38 26 39 29 41 34 / 40 20 50 50 30 60
Pullman 38 29 41 32 44 34 / 50 10 30 30 10 40
Lewiston 41 34 46 34 47 37 / 40 20 30 20 10 40
Colville 40 21 39 27 42 32 / 20 20 50 50 40 70
Sandpoint 38 25 38 30 40 33 / 60 40 60 70 50 60
Kellogg 34 28 36 27 39 34 / 70 70 50 60 20 50
Moses Lake 47 29 49 32 47 34 / 10 0 10 10 20 60
Wenatchee 45 32 45 33 46 35 / 10 0 10 10 20 60
Omak 42 27 41 30 43 33 / 10 0 30 20 30 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Storm Warning until 4 AM PST Sunday for Central Panhandle
Mountains-Northern Panhandle.
Winter Weather Advisory until 4 PM PST this afternoon for Lewis
and Southern Nez Perce Counties.
WA...Winter Weather Advisory until 4 PM PST this afternoon for East
Slopes Northern Cascades-Northeast Blue Mountains.
Winter Weather Advisory until 4 PM PST this afternoon for
Northeast Mountains.
&&
$$